One more suggestion.... could you get him to go to a clinic/doctor with you and have the doctor explain the gestational age to him. It's going to be really hard to argue with a medically trained professional about this and if he does, then you probably know where he stands. Also please, please,please tell him to wear a condom or go get a vasectomy if he doesn't want a kid!!! He has a way to prevent and he needs to use it everytime. He's just as much responsible as you.
Thank you...there is alot of dishonesty. On his part so maybe that's why he is act luck that....he also trips on people from my past before him like a letter someone. Wrote me he found...but all before him so I wouldn't. Understand you that bothers him...we have a communication problem this I do know
If he will not listen to you telling him how pregnancy is calculated, go to the library and get one of the books (Your Pregnancy Week by Week or What to Expect While You're Expecting) that has an explanation, and make him read the explanation.
He doesn't sound like he would believe any explanation from the Internet, but if you think he would, here is one from another site (and there are a lot of others): "Gestational age is the common term used during pregnancy to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman's last menstrual cycle to the current date." Point out to him that it says the first day of the woman's last period, not from the day of conception. When a doctor gives a date, he starts the count on Day 1 of the period.
It sounds like you guys have a boatload of other stuff. He's shocked and suspicious, you're shocked and hurt, and back and forth, and back and forth. If you want to save the relationship (and the baby), go to a counselor together and lay it all out. Tell him it's time to stop all the drama and decide where the two of you really are.