“Plan B”

Hello, Im a 23 year old woman and I took a Plan B 2 months ago and just one week ago started getting terrible cramps. Worse than I’ve ever felt before but I’m not on my period. I’ve been having to constantly take ibuprofen to help. My last 2 periods after taking the plan b i didn’t have any cramps. On top of that I’ve been having a constant yellowish discharge for the past 3 weeks that has a distinct odor. I took a pregnancy test and it came out negative. I’ve never had any of this happen to me before so i assume it’s because of the plan b but i’m not sure. Should I make an emergency trip to the hospital?