Can you REALLY have symptoms at 7dpo?

I feel like you can't. At that point the egg isn't even implanted, let alone producing enough hcg to cause any hormonal changes.

I'm 7dpo so I'm on a few threads here with my cycle buddies for the tww, and everyone keeps asking about symptoms already at like 6-7dpo. I'm really skeptical that you can have symptoms that early. Mayyybeee when you hit 10 or 11dpo, but that still seems early for any kind of symptoms besides a positive test. As much as some people may not want to hear it, I think it's all psychological. 🤷‍♀️

Prove me wrong? Should I be feeling different if I'm actually pregnant? If there's a scientific reason for it I'll 100% change my mind, I'm just looking for other opinions since I'm really curious.