Girls help!!

So I went to the doctors and I told her some of my symptoms and they're pregnancy symptoms but I'm on the pill, and I used to take it like quite late. Like about 15 hours after my last pill, but I'm off the pill now for 2 days because of mood swings etc..I have unprotected sex all the time. And I've had pregnancy signs like 3 weeks ago for the whole 3 weeks I've had mood swings, growth in breasts, sore breasts, really bad nausea and vomiting, sore back, etc and I took the pregnancy test about 6 days ago and it came up negative, but I got my period 3 days ago, and I went to the doctors today and she told me to take a pregnancy test in 8 days from now, but how can I still be pregnant with a negative test and a period? What should I do? Take another test and the doctor insisted to see if I'm pregnant or not? Could I still be pregnant after getting my period? So confused. Please answer with what you would do thanks girls