Help please!!! Don't judge! Nobody is perfect

I had intercourse with 2 diffrent men within 3 days, and I became preg, one of them had a vasectomy 11 years ago and of course the other is fertile! My EDD should of been June 11th, but by my 1st ultrasound it's June 6th!!!! So I'm guessing maybe I ovulated early ? Or can the ultrasounds be off some? I did have non invasive DNA by blood done by the guy that had a vasectomy and it came back 0 percent that he wasn't the father which is what I was hoping for but I still wonder from time to time if the test is correct and I still freak out, could that be from guilt? It's getting close to my scheduled c section so I'm starting to freak out again