Advise please!

Hello! I came off my birth control just before Christmas, I had a bleed, but it was more of a withdrawal bleed I think.. I’ve had really sore boobs, been feeling a bit nauseous and a few period like twinges. I’ve also been so moody and emotional especially today 🤣🙈 according to my app I’m two days late.. I took a test this morning and it was negative.. any ideas?! I’m trying so hard not to let it play on my mind and get too obsessed about it all but it’s so hard and this is only my first month of trying!

Thanks in advance ☺️