I have had lost of Appetie,Diarrhea an a late period I have had a regular period for about 4 months now until now could I be pregnant?

If you are having sex, yes you could be pregnant. If you are having unprotected sex--that likelihood does increase quite a bit. My name's not EPT, so I can't tell you DEFINITELY if you are pregnant or not. I can suggest that you go take a pregnancy test (best with first morning urine). Good luck!