Just found out im pregnant but im scared...

Please don't judge I really need your opinion... So I left a 13 year relationship 8 months ago and I've been seeing and sleeping with one guy until last weekend I went out of town and had a one night stand... Now I was in my fertile days when I was having sex with the one guy and I just ended them when I had the one night stand...I really want it to be the guy I've been seeings baby but I'm so scared that it could be the one night guy...I'm going to post my calendar so you guys can see the days...I had sex with the my main guy the 25 26 27 and the one night on Friday the 31 almost Saturday because it was well after midnight... Please give me advice and like I said please don't judge I just left a long hard relationship and I just need honest opinions thank you so much