Plan b effects normal or not?!

So on June 26 my boyfriend and Ihad sex. Unprotected sex. When he went to reach for a towel he ejaculated on my butt, which fell and hit the lips of my vagina. We cleaned off and thirty minutes later had sex again. I know really stupid. On June 28 I took plan b. at first I experienced ldizziness. Then when I got home later that day I became extremely tired. Throughout the next couple of days I didn't really experience any symptoms except tiredness. Then two days ago, I started experiencing plusing in my abdominal, pelvis, back and leg. They stopped Everytime I drank water. Then my navel began to look sunken in. When I press on it, it only hurts in my stomach. I have been experiencing lost of appetite. And my stomach and pelvis began plusing again. I'm also experiencing strain on my right rib side. I feel really constipated but it's hard for me to go. I feel like my period is about to come on but then I wind of peeing. My belly button still looks sunken in. Is this normal. My period isn't due until the 13th either.