Skipped my period on birth control

I skipped my period last week I been having sex all week my stomach is cramping so bad right now only on day 6 I noticed milky discharge and my stomach is bubbling and so upset .. it feels like my period is starting but it can’t be it’s my first day leaving my bed in days and I haven’t been eating a lot I feel sick but can’t explain it could it be because of stress or something I can’t be pregnant has this happened to anyone