Can soeone help me figure out my possible due date?

I have a kinda irregular cycle, af comes every 37/38 days. My last af was 12/8/2019. I had sex 12/28 & 12/30. My period should’ve came 1/13 or 1/14. I got a positive digital hpt. I’m trying to figure out when I might be due. I tried the calculator on google and I feel it’s wrong Because of my cycle length.