Unprotected sex, I’m scared !?

So about 5 days ago I had unprotected sex with this girl I’ve been seeing for 4 months. So when I stuck my stuff in her I was really hard, I started going for her spot so she’d feel good. On my end my stuff wasn’t feeling anything but I wanted her to feel good so I kept going even though it wasn’t enough to make me want to ejaculate. Then when I finally starting feeling good my dick went limp and she pushed me off. So I was confused because I know I didn’t *** so I just wondered why I went limp my junk didn’t have any left over sperm and I definitely didn’t feel like I wanted to ejaculate when I was insider her. So i think my junk went small because I got bored. So she asked me if I ejaculated & I said “I don’t think so” so we got mad at eachother and argued then we both just figured we were overthinking it. So we stopped taking about it. Then just tonight I brought it up again and told her to take a test to make sure she’s not pregnant she got mad at me and told me too stop talking about it that I was freaking her out. We both know we can’t have kids cause we’re young but she’s freaking me out cause it’s like she’s keeping info to her self and the last text she sent me was we need to not talk for a couple days. So she really had me worried because I’m not ready forever any kids I’m too young and dumb