So I am 16 and well under the weight limit weighing at around 110. and me and my boyfriend ended up having unprotected sex(it was my first time and his) August 2nd that only lasted like 30 seconds, if that. He did not ejaculate inside me or finish at all so we didn't think there was anything unsafe about what we did. Later I found out pre cm can still get you pregnant so I took the pill about 18 hours after on August 3rd. I've been freaking myself out that I'm pregnant and he and I are both very worried. I'm having lower abdominal pains and my breasts feel tender up around my lower armpits only about 10 hours after I took it? I have a very irregular period and can go months without having one so I'm worried that I may never see bleeding and could this affect the efficiency of Plan B? Since my period is so irregular I'm afraid that i was ovulating the time of intercourse. Please help me, I'm desperate for answers and am so nervous.