is it period cramp or cramp in early pregnancy

Hihi mummy's out there .. I had 3 child and now if I'm pregnant it will be my 4th . I had a bad cramp this 2 days ... I had nvr missed my period . Today 2nd day missed period. I'm waiting to wait till 1 week then I check pregnancy test. But now my tummy had alot of cramp from morning to night couldn't sleep well . When I eat then the cramp will go , but for a moment only . Then it comes again ... Help .. I don't have experience like this with all my 3 kiddos .. ?