Could I still be pregnant?

My last period was november 19-25. This is my first month off of birth control so I dont remember the exact number my cycles use to be before I got on birth control but I know it was no longer than 32 days. Tomorrow will be day number 36 with no period. I took a pregnancy test yesterday and it said negative but ive been constipated and bloated and needing to burp constantly the past 3 days. I read a lot about women who couldn't get a positive urine test but got a positive blood test. Anyone's input would be greatly appreciated.