not pregnant but missed period 2 months

Hey ladies! I am on the pill and take it every with very few mess ups. My boyfriend and I have regular sex without a condom, but he does not come inside me. I have completely missed my period for the past 2 months. I have taken 2 pregnancy tests that say I am not pregnant. I have also had all of the symptoms (headache, tender breasts, breakout, fatigue) of pms at about the time of my period. Is there a chance that I could still be pregnant ?  Is it normal to miss consecutive periods ?? ADVICE PLEASE 💕💕💕