Unprotected sex

My boyfriend and I recently had sex for the first time, but I’m so scared now. He’s in the military, so he’s not here and we have crazy different time schedules so it’s super stressful to talk to him. I don’t regret having sex, but I regret being unprotected and off the pill. I don’t want a kid yet and I’m late on my period, but I feel like I’m over reacting too. Any advice, other than the obvious use protection next time?