Hi.. I'm 28yr old.I and my husband are having sex for the past 2yrs but always protected.But last December we had unprotected sex and I missed my period for 2months and I had lower abdominal pain.I had pregnancy test but it gave me negative result.later it was normal.Again we had safe sex for 1month and my periods were normal till September.Now again in September after my periods we had unprotected sex.I missed my period in October and now till date I did not get my periods.I had pregnancy test on 21st day after I didn't get my periods but it was negative.I don't have any symptoms of pregnancy but I have a mild pain in my lower abdomen.Please advice.