Quick question if anyone can help

Amber
I'm 25 and I've been with my boyfriend for almost 5 yrs and this never happened before... recently every time he goes inside me my period will get messed up. I will miss my period for 2 months then I will get it and it will be very heavy anyone have any idea as to what is going on? I made a doctors app. But would love some suggestions to ease my mind because doc. Is not til nxt. Week.