so i use to have regular periods once a month then iwent on the pill for 3 months my period was late after istopped but went back to normal once a month, iwas on the week of expecting my period and then i had oral sex ; waiting for my period no period came, waited 2 months still no period i recently had sex 3 weeks ago and my pregancy test came back negative and i still havent got my period after 3 and half months ! should i be worried ? im scared that its affecting my ability to have children ?