My (24F) husband (30m) is accusing me of cheating because of his vasectomy, How to clear my name?

TLDR- I'm pregnant after 2 years of trying and now my husband believes I'm cheating because he got a vasectomy without telling me.

My husband and I have been trying for a baby for 2 years; two days ago I found out I was pregnant and was over the moon and couldn't wait to tell my husband.

To my surprise, my husband told me that was impossible because he got a vasectomy and accused me of cheating.

I never cheated on him For two damn years, we have been trying for a baby only for him to hide the fact that he got a procedure done to prevent himself from having babies. I was always upfront with him that I want children and even work in childcare because of how much I adore children so the thought that he'd lie to me and have me get my hopes up and everything is hurtful.

My husband always told me God will bless me with a child when the time was right believing that I may never get one when I became worried. I just don't understand why he'd lie to me.

the fact that he's now accusing me of cheating when I have been nothing but faithful just adds more salt to the wound, I know I have been faithful and I know there must be some expansion on how this pregnancy happened even with the procedures my husband has gone through.

right now I am at a loss on what to do, my husband has been telling people I cheated on him and now my own sister won't even give me the time of day.

I just want this to be all resolved and can't wait for the baby to be born so we can get the paternity test done: I have been crying non-stop because no one seems to believe me.

my husband even suggested I abort the child we have been trying so hard to conceive. I still love my husband but I don't know if I could forgive him for putting me through this but want to still so my child won't be raised in a broken home like I was.

what do you guys suggest I do to clear my name?

how do I get my sister to hear my side of things?