No period since stopping BC

24 female. I've been on Beyaz birth control for over 4 years. Recently decided to stop taking it and await a pregnancy with my long term boyfriend. It's been about 6-7 weeks since I last took birth control and I've been tracking periods and sex for the past year. Periods occurred every 28 days while on birth control and I even lately started bleeding during ovulation. Since stopping birth control, I have had no normal PMS symptoms or a period or even spotting. It's been 15 days since my missed period and all pregnancy tests have come out negative. Do you think my body is just getting used to not having birth control? Should I take a different pregnancy test? Opinions? Thanks in advance ♡