Does Stomach Pain And Menstrual Cramping Indicate Pregnancy?

Hi,

I had my period on 11 jan 2014,on the 6th day i.e on 16 jan 2014,i started using ova mit tablets for 4 consecutive days,one of the Gyno advice me to take those tablets because i was having difficulties on conceiving.and on day 10,12 and 14 we had sex with my husband.I was expecting to have my next period on 7th february,my cycle is 28 days and has not changed for years,but up to now i havent seen my period.Am also having stomach pain like am about to get my period.Is it possible that am pregnant already?