Nervous, but not so nervous.

My boyfriend came inside me for the first time today. We discussed the outcomes and will prepare ourselves for whatever does or doesn't happen. I've been on Nexplanon for a month (Jan. 27th). I kind of stayed on top of him for a few minutes before I got up to use the bathroom.

Do I have a high chance of being pregnant? Have you ever got pregnant using Nexplanon? If I am pregnant, how will I know?