Do you think I could be pregnant?

Ok so I;m supossed to get my period because its tuesday and I am on birth control so my last pill was saturday. I have crams like i have it but there isn't alot of blood. There is only blood when i put in a tampon and its like not that much just like some brown and red and sometimes when i wipe there is a little blood. All the times that I have had sex we have used a condom and they did not break and i did not miss one day taking my pills. So should I be concerned or no? Thanks for any help :)