Can you feel it when he cums? What does it feel like?

When my boyfriend & I have sex he always pulls out before he cums. But recently, right before he pulled out I felt like a warm burst. Would that have been him cumming inside of me?

Sorry if it’s a stupid question, I’m not very experienced sexually. We’ve been together for 2 and a half years & I’m barely 18 so he’s the only person I’ve ever been with.