Can Plan-B Cause Weight Gain?

I took plan B twice over 3 days mid July. I am on regular birth control but had just finished a round of antibiotics for a uti about 4-5 days before and took plan B as an extra precaution. I have had my period since then and have had negative pregnancy tests, which I took as a precaution. Since I took the plan b pills I have gained weight, had abdominal pains (sometimes even by my belly button),back pains, blaoting, burninf in stomach, headaches, and ended up getting another uti, which I was treated for about 2 weeks ago. I am concerned that plan b messed up my system since I am.still having side effects. Is there any cause for concern or action on can take to get back to normal? If it needs to run its course, I just want to make sure there isn t a bigger issue that needs addressed.