Figuring out how far along I am?

Sarah

I went off my pill on Nov 17 and had my withdrawal bleed on Nov 20. It lasted three days. I never got AF but randomly took a test on Jan 6th and had two BFPs! Had my hcg measured on Tues (264) and Thurs (523). Have a sonogram Wed (seems like ages from now) so we can get more data on how far along I am. It’s killing me not to know so curious if anyone has any ideas about how far along I might be? I was on the pill for 14 years and always had a normal 28-30 day cycle except just coming off of it where I never even had a real period. Thoughts?