Help!

Today is the day I ovulate (according to the app, even though my period has often been off of calculations and has been earlier before or later) and last night my husband and I had unprotected sex. We weren't really planning on having sex and it just sort of happened, and he pulled out when he felt like he was going to go and then stopped and looked at me saying he might have gone a little bit in me. I'm not on any other form of birth control because the hormones cancel out my anti-depressants and I'm freaking out that I could get pregnant and I can't afford that right now. How high are my chances of pregnancy? I don't know what to do! Comfort me? I'm scared. 😰