What the heck is my due date?!

Ok so I am just so unsure here lol obviously I'll find out for sure when I have my 1st ultrasound but maybe y'all know more than me!

I have long cycles that are typically 35-39 days long.

When I check due date based on cycle length of 39 days it says I'm 6w2d. But then when I put in 28 days I'm getting the same. However, this app is saying Im 4w5d.

My last period started on May 30th! What do you all think? Lol I also am not sure when I ovulated last month!

Thanks! I'm just curious what everyone thinks. Not that big of a deal! I have a dating ultrasound on Aug 9th :)