Period while on pill??

So I just started taking sprintec on October 23 (Sunday starter) now today Oct 31 I have slight cramps and basically feel like I do on my period I even started bleeding (nothing heavy) and the day before I had very slight spotting but if I were not taking the pill this would be the time my period comes. I just started the second week/row of pills. Is this normal?? I did have sex several times between the 28th and 30th (unprotected, but then used a spermicide condom to finish)