What Causes Vaginal Itching And Frequent Urge To Urinate After Intercourse?

Question: Hi, Im 18 years old and about 3 weeks ago I had sex with my boyfriend and after an hour i was feeling weird down there.. no burning or itching but uncomfortable.. the next morning i was experiencing some symptoms like urge to pee all the time, and when i went it was very little pee, sometimes when i drank a lot of water i peed normal. discomfort during the day.. kinda like burning and after i was done peeing i felt a very uncomfortable and painful feeling, like pressure..even if i was peeing normal but no pain or burning during peeing. No blood, no smell in urine, no abnormal color in urine, no abnormal discharge, no itching but i had pain during sex. Ive never experienced something like this before because at all so my mom told me that it was probably a yeast infection because i just started having sex a couple months ago and its normal.( I DIDNT GO TO A DOCTOR SO I WASNT SURE WHAT IT WAS)I never use any kind of medication at all.. so i was trying to avoid pills but I used Canesten 1 and it didnt go away.. the urge to pee went again but still something there. A week later i was having the urges to pee again and all of the symptoms like in the beginning. A friend of my mom that has had this problems before told me to use these products: Genestra - HMF Candigen Ovules (6) 1 every night. / NFH D-Mannose XXXXXXX with pure cranberry juice with no sugar and water 3 times a day after meal. / Cantharis 30C, 5 pellets 3 times a day with no food until the symptoms were gone or it could make it worse. She said that probably the yeast infection went to my urinary tract so it was important to take treatment for both. At the first day of doing this my symptoms went away, just the uncomfortable pulse after peeing was still there but not as painful as the beginning. At the 3th day everything was gone so I stopped using the Cantharis 30c and I didnt apply one ovule the next night because I wasnt in my house so I couldnt but i was still with the Dmannose and cranberry juice. Everything was good but the day later i woke up and i was feeling uncomfortable down there again.. not as bad but not perfect as the days before and i had the pain after peeing again. It went away in about 5 hours.. i was back to normal and i didnt have the pain after peeing at all.. That night my boyfriend and I tried to have sex again because we havent since i started with this. It still hurt.. not when it goes in but i fill kinda the same pulse as when im done peeing.. and i was feeling the need to pee during.. i didnt enjoy it at all so we stopped. I went to pee and i didnt feel the pulse and i wasnt hurting at all, the pain was just during sex. Im tired of this so on tuesday because im not even sure what it is.. i went to a clinic, i described the symptoms to the doctor and he told me it wasnt a yeast infection.. that it was just a UTI and prescribed me an antibiotic of a single dose.. Im not a big fan of those things, i believe that just make the symptoms go away but the problem is still there and it can kill a lot of things in the body and ive heard antibiotics is the main cause of yeast infections.. and he didnt even took a test or anything to really be sure of what it is.. because i dont have the urges anymore is just the pulse after peeing and pain during sex.. you cant really tell what it is. He was telling me that if i dont take it it may go up to my kidneys.. i went to a lab the next day to take a urine test. Im waiting for the results. Ive been good these days, sometimes i feel the pulse, sometimes i dont, sometimes is not as painful as others. Is very weird. So my question is.. what to do you think it may be? and if its a UTI why isnt gone by now?? what can i take naturally to make it go away or something not as bad as antibiotics? and if it wasnt a yeast infection, was it dangerous for me to take the cream and the ovules?? (i just used 4 ovules, didnt use the 6) Im worried about that.. because yesterday i think i got my period.. but is early.. it usually comes around 28 or a bit later and it was like watery pink brownish and with blood clots, is usually like that when my period is about to start and a couple of hours later its normal blood. But hours later it was the same.. or nothing i woke up today and the same.. in the pad is some brown blood but i wipe and its watery pink and brown with some clots, and i have i started having big red clots.. Im scared cause i usually feel when my period is coming.. i really feel it and this time i didnt.. i dont usually have cramps but i feel a little bit sick a day before and i didnt. Im freaking out because ive heard it could be pregnancy (which i dont think it could because we ALWAYS use condom and we always check that its okay after) or cervical cancer or i dont know.. im really worried.. ohh and two days ago i got sick.. like the flu, my boyfriend was sick too so i probably got it from him, but i dont remember the last time i was sick.. my diet is very healthy, ive been vegan for 2 years now and i never get sick even if someone around me is. I eat a lot of fruit in a daily basis but i stopped for the past to weeks because of the yeast infection so i think thats why but yeah i dont know if it could have something to do whit my system.. please help

Thank you so much, yes i will do that. But do you know if usually a single dose of antibiotic is enough? or what to do you usually prescribe? How long would it take for a UTI to become something serious? my tests arent back until 2 more days and i dont know if i should wait more.. its being 3 weeks.
And just the part of the ovules and cream.. was it dangerous for me to use that if i didnt have yeast infection? my doctor said is very strong steroids so im worried..

Thank you! this literally keeps me awake because im scared.. haha
I will do that! so in case that i have to take the antibiotics, what can i do to prevent the yeast infection because of them? taking probiotics too?

Hi again, my results were supposed to be for today.. but they told me that they found a little bit of bacteria but the urine culture was contaminated so they coulndnt tell exactly if i have it or not.. and i needed to take another sample so i did and i have to wait for 3 more days.. but im very worried because i was fine.. i wasnt feeling the pain after peeing this past days, just sometimes and very low but i drank a bottle of water to do the sample again and i felt a little bit weird, after 2 hours im feeling the symptoms again of going to pee very often and it hurts after i finish. i dont want to wait more and make it worse, what antibiotics should i take that will be 100% effective? and what probiotics can i take to prevent a yeast infection because of them? im desperate and very worried because ive been reading about IC cystitis.. its very scary and i relate to a lot of people who have it in those symptoms.. what do you think? is it possible for a simple UTI to become a IC cystitis? and whats the difference of a normal cystitis? im very confused.. please i need a detailed answer im freaking out.. and please tell me what can i take for this