confused about due date- help!

anon • 🤫
So, long story cut short.
Been ttc 3 years. Had 2 rounds <a href="https://glowing.com/glow-fertility-program">ivf</a> (one failed last dec, and one resulted in chemical pregnancy in May).
After chemical i had a bleed - started 10 May. Had sex twice lol - once on cd 16 and once on cd21 (i ovulae anywhere between cd15-22 so narrowing down ovulation for sex timig is hard!).
Missed period did test bfn. Thought it was the <a href="https://glowing.com/glow-fertility-program">ivf</a> meds and chemical pregnancy that had messed up my cycle and i am like 3 weeks late.
Yesterday i felt sick all day. Took another test thinking just confirm the bfn. Cant tell when my missed period should be really my dates are all over the place. And i got an ultra positive test within seconds  and a 3+ on the digital. 
In shock. 
Cant figure out due date/how many weeks and days i am right now. Glow says 7wks 3days, another app says 8wks exactly.
Help! ❤️❤️❤️❤️