Is it safe to take pain relievers for cramps while on the 'pill'?

im about to have my period real soon now, i can feel it. and im suppose to take my contraceptive pills for the very first time. i get really really bad cramps, the doctor said it will be lessened by the pill, but what if there is still pain that i cant take? is is safe to take a pain reliever? is there a specific brand? and how much will the painreliever affect the contrceptive pill with regards to birth control? will it cause the pill to lessen effectiveness? sorry many questions, i should have asked my doctor this but it takes a week before i can talk to him again and im about to get my period in a few days.