[awst3n]

My girlfriend and I had an evening that worried us. I think now when I think about it I'm the worried one. It is now behind her.
The advice of you all.

We have protected sex 90% of the time. There has been three or four times where we had unprotected sex. This past week we were on vacation with my family and our room was connected to my parents room.
We had unprotected sex, I guess you couldn't call it sex. We didn't want noise so it was just me inside her. We both wanted to feel a little. We were laying there, I was inside her (no thrusting) all of a sudden I feel my dick throb twice. I pull out and it throbbed again.
I felt no pleasure as if I came. I felt myself and didn't feel any cum. I told her what happened it we stopped. A day and half later I tried to get her to get Plan B, she didn't.

I'm worried. What should we do?
Is there anything we can do now like a Plan B?

Thanks