How am I sapose to handle this situation if its his kid?

So I have been with my husband since 11th grade we are now 26yr old. We had a baby when we were just outta highschool ans another 2yrs after that.. We got married in o8 and had problems with always fighting so in o9 I moved out with the kids and we were seperated in this time we saw other ppl. He met a grl tht he dated for 3mos and found out she was kinda crazy like possesive and clingy so he broke it off but went back a mobth later an slept w her.. She had a baby last july 22nd and was induced and had a 9lb baby the date they had sex was nov 7th tho.. Anyway she was goin around saying its his kid but has tested 2other men I know of and now his test is nxt wk. Im so scared to know results. What do I do if its his? Do I stay?