Should I call my ob?

I'm a few days away from 10 weeks PP and i have yet to have a period. Have had a few negative tests the last one being last week. Have not taken one since I'm not breastfeeding at all. Just trying to see what I should do. I have had 3 kids and I got mine at 6 weeks with my other children. I have had unprotected sex with pullout method but it isn't 100% at all.