I took plan B a few hours after having sex on March 21st, but realized that I think it was during the window of ovulation. (My last cycle started on March 12th, lasted 7 days and is usually about 30 days in between.) I've taken plan B a few times over the last few years, and had previously only experienced some cramping within the first few days of taking it. It was 2 weeks ago that I took the pill, and now I'm experiencing symptoms that seem to be pregnancy symptoms. About a week ago I started getting lightly nauseous, then this week I've been severely nauseous. I also have been extremely emotional (weepy) for the last week or so, which is not normal for me even during my cycle (the last time I was this weepy was when I was previously pregnant). A few days ago I started bleeding and have had some light cramping, but my period isn't due for another week from today (so I'm concerned it's implantation bleeding). I'm still super nauseous, and extremely fatigued, and have had slight lower back pain (which I also haven't had since my first pregnancy...that was actually my only symptom at the beginning of my first pregnancy before the morning sickness hit). I'm just confused because these symptoms are so different from my previous experiences with Plan B, and not what I normally experience with my cycle (even when I previously took Plan B). I took a pregnancy test this morning, but it was negative (although I think it might be too early since my period wasn't due for another week). Could I possibly be pregnant?