I had a bizzare sensation early on with my first pregnancy about 3dpo, it felt like being stabbed with a knitting needle several times from the inside, near where my ovaries were. It didn't hurt, just felt like pressure. I thought at the time how weird it was, but didn't have a clue I was pregnant at that time. It was only when I got my BFP a week later that I remembered it, and wondered if I had felt the fertilised egg popping out of the fallopian tube! Maybe because it was bigger than an unfertilised egg which I wouldn't usually feel! Sounds crackers but I've never felt that feeling before or since, it was very odd and distinctive! I've never felt any sperm fighting lol but our bodies are amazing, you just never know!
I've also felt the moment of implantation in all my pregnancies (except MC strangely), with funny pinching/stabbing pains very low down, like something attaching itself to the inside, they're very distinctive pains that i've felt around 7 - 8dpo in 3 pregnancies now, to the point where I knew I was likely to get a BFP even before testing. In my second pregnancy I thought I was still waiting to OV when I felt that pain (just come off the pill and hadn't had AF) so it wasn't my brain playing tricks knowing it was 7 dpo either lol.
So yes I definitely think it's possible to feel strange things in your body if you're in tune. But equally I think our brains do play funny tricks sometimes when we really want something a lot. I'm keeping everything crossed for you that it's a good sign lovely! Xx