Plan B...

Hey. So I'm 17, and I've been with my boyfriend for a little over a year and we never had sex. Until yesterday. My period had just ended the day before and the moment was right and it was amazing but we didn't use protection.. And yes I know its incredibly stupid and believe me, I'm paying for it. Anyways, we got the Plan B pill this morning and I took it a little over 16 hours after the sex. Now I've always had complications with my period and I have a history of women in my family losing their ability to have kids at a very young age... I'm really scared that I just killed my only chance of having a baby. But I'm just not ready and it would ruin everything. I'm really torn and I feel really guilty. I know my boyfriend is upset for the same reason as we cried together after I took the pill... I don't plan on having sex again for a really long time. Honestly, I'm not sure if I'm more scared I do get pregnant or I don't... Any advice or input? I could really use some support. I don't really have any family or friends I can go to for this..