Help! Possibly pregnant or just going crazy??

So I have the Mirana IUD and I have had it in for a little over a year now. When I first got it, I had some periods but then they started going away. Eventually, I would cramp and stuff around when my period was supposed to be but I never bled. But the last couple months I’ve had periods where I would bleed. It just randomly started up again. When I got the IUD put in, I wasn’t sexually active at the time. I had been for years before and I knew I was going to again and I wanted to get off the pill. Recently, almost a month ago, my new man and I started having sex. Mind you, this is the first time I’d had sex in like 3 years. We used condoms for most of the times but sometimes we didn’t. And one time I let him cum inside me, but I checked and I wasn’t ovulating at all. I know the IUD is still there because my man has told me he can feel the strings when we have sex. Occasionally I get cramps after we have sex, but he likes to go really deep. So this month, I never did bleed. I had really bad cramps (that felt like my normal period cramps) for like 2-3 days and then some really really light bleeding. Like barely needed a pad light. So now I’m freaking out because I’m wondering if I could be pregnant and it was implantation bleeding? Or is this normal and the bleeding could just be from our rough sex? I haven’t had any other symptoms and I’m terrified to take a test. So is this all normal? Could I really be pregnant or am I just letting my thoughts get to me?