I Was On Camrese Lo Birth Control Since August. My

I was on camrese lo birth control since August. My last period was in the beginning of August as my gynecologist from where I used to live, suggested that I skip my period in between packs so my ovarian cysts don't come back. Well I've been off my birth control for 4-5 weeks and I still haven't gotten my period. Usually no matter how long I was on birth control, my period would come 1-2 weeks after I get off. My last month of birth control I was really forgetful and would take it hours late and sometimes days late or the next day. The last time we had unprotected sex (other than this week when we decided we wanted to try to conceive) was 8 weeks ago. Is it possible I'm pregnant but it won't show up on a pregnancy test? I've taken 3 since then and all were negative. I've been getting a lot of symptoms though