im worried help!! ...need advise ..no period but negative tests

I have missed my period now for 11 days and I'm getting quite worried now as I've taken countless tests for pregnancy and all negative so far ....me and my partner are trying for a baby since a month ago but we actually didn't have sex when i was suppose to have been ovulating last month on the 22nd march ...I'm worried now as all tests come back negative i actually feel nauseas at times and want to eat random thing i know its probably subconcious i just want some oponion before i go to the doctors