I can't fully understand what you're saying, but from what you've said this is the first time in a year you've had sex. If this is true, the movement would be gas and nothing more. I'm not sure why your belly button would be going in and out. I've never heard of that before. If you suspect pregnancy, take a test with first morning urine in about a week or so, but if you got a normal period after you had sex, I doubt you're pregnant.
I dont think this is normal i would tell to see the doctor for you .