I am scared i might be pregnant, my period is late & the condom would slid off&made bubbly noises?

My period is about a week late, and it's already the end of the month. I'm scared i might be pregnant but there are other possiblities like that my body could be changing it's cycle too? We always have protected , but we have '!' cards and play games sometimes, and one time the condom kept sliding off a little bit and was making squishy noises, like there were air bubbles. I couldn't have a baby, but i couldn't kill my baby either if i am.