2 weeks late

Hubby and I are ttc # 2! I stopped my birthcontrol at the end of december and had a regular af in jan & feb! Should have started 3/1 but instead I had very light brown spotting(only when i wiped) and cramps 3/2-3/5! Yesterday my boobs started feeling tender and i am having cramps again! Took a test on 3/3 & today and both were bfn! Could this be from stopping birthcontrol or possibly preggers?