Pregnant and af?? possible??

Idk its mad of me i guess but i am feeling something inside my stomach,i still feel pukish,its my CD4 had light flow n while my af i usually have diarrhea this time its constipation(tmi)!! I had normal flow like heavy,heavy,medium n now light!
​Can it be possible to be pregnant and get af?? How should i figure it out??