Need Medication For Irregular Periods

I am a 25 year old female with very irregular periods. My last period was March 23-28 of this year (Four weeks ago). I have already successfully delivered a child in 2011, but did not get a positive result until I was 10 weeks along and my partner and I tried unsuccessfully to conceive for 3 years before I finally conceived with my first child. Now we are trying for our second child. I am having all the symptoms of pregnancy, including: mood swings, nausea, vomiting, tender and slightly swollen breasts, some fatigue, and slight cramps that vaguely resemble menstrual cramps. I took a test that ended up negative, but I am still experiencing all of the same symptoms that are nearly identical to those I had with my first pregnancy. I don t have the funding to go for a blood or hcg test at an actual doctor, but I was wondering if the reason my test wasn t positive may be low hcg... (I thought this may have had something to do with the fact that it took so long for a positive result the first time around!) Please help, I am starting to feel like a crazy person!