My period started on 30th sept but mine are highly irregular due to pcos so I don’t know I’d say around 3 x
I would suggest calling your obgyn and letting them know you had a positive pregnancy test but now you have some light bleeding and the pregnancy tests are not as bold now. They can do a blood draw to check that your hcg number is elevating as it needs to for a healthy pregnancy. I’ve had very similar experiences and it helps to know what’s happening 🙏
How far along do you think you are?