Worried about paternity

Ex is leaving soon but we were active around this time as it was supposed to be our 5 year anniversary pretty close to this 3 ish years trying no baby sadly then 7 days after conception I switched from spermacide/throw a condom on before he came with my “sugar daddy” (now boyfriend/baby daddy using that method for 1 month) to doing it raw.

So is the conception date just a whole week off/method failed or is it a higher likelihood that it’s my exes?

Baby is also measuring ahead as well as conception date being 7 days earlier than the fully unprotected sex

Just wanting thoughts