I had unprotected sex and I wasn't to sure if he cummed in me or not so I had him go get plan b and I took it after he got me from work and i took it within the 4 hours when it happen . So I took it and than I had my period 2 weeks later than it was normal for another month and than now I haven't had a period for March and April . Is plan b messing up my period or should I be worried ?