Staying out way later than he said

Qu

So my SO was supposed to work until 10 pm last night he spoke to me at 856 pm and then again at 1215 am we have been together for 8 years and never once has he ever cheated but we took a break last November and he started working as a mailman and saw a female well call her lashanae. He told me when we weren't together that he really liked her more than me so when we got back together I always had this sinking feeling that I'm not gonna be able to compete with her. That in the back of his head he's always gonna like her more than me because she's so new and gets him more than I do since they work in the same field. I don't know if it's my hormones playing a part in this but I feel like the further I get with this rainbow baby the bigger I get and the more he's more attracted to her than me. Since we've been back together and found out we were pregnant he doesn't bring her up he tells me he loves me and he always reassures me as to how beautiful I am. But it just keeps nagging at me that he's just saying that and he doesn't actually mean in. How do I know that these late work hours between the two of them are actually late work hours and not the two of them sleeping together and or going on dates. Please don't judge me some advice would be very helpful.