Tw pregnancy right after miscarriage

So my hcg levels after my miscarriage did drop down to 0 and it was a very early miscarriage not a lot of bleeding or anything crazy… but I got pregnant before I got my next period and I won’t know how far along I am until the 17 and it’s driving me insane😅 does anyone know how you would calculate that, would it be the first day I started bleeding like how a period would be or 2 weeks after when I would have been ovulating…. I’m just really trying to figure out how to get a rough estimate, I started bleeding April 12 it lasted about 3 days and was very light and I got my positive tests may 27, my hcg is doubling and everything is going okay I just can’t help but to worry😩