“Lymph Node”

Hi everyone. So I lost my virginity about a week ago today. It didn’t last long at all because it was both of our first times and it was painful for me so we decided to stop. I’m on the pill (not that that applies in this situation) and he was wearing a condom. About 3 days ago, I found a lump on my groin, basically on the area where the sides of your underwear touch. Like in between my upper thigh and pelvic area. The next day I got a fever and have sore muscles. I’ve been dealing with that over the past few days. I went to the doctor yesterday and she told me that it was a Lymph Node but then asked me if I have ever had sex. I said no because my mom was in the room but I’m wondering if this could be something different had I said yes. I don’t think it could be because we didn’t really have sex long enough or have contact in a way for something to spread. I want to note it was his first time too so I don’t think he’d have an STI either. Am I just overthinking it?