Wedding concerns

Ok, so I dont if I am over reacting or not. But my wedding is April 30th of this year. My fiance and I both have been married to other people before but this is both of our first actual vig wedding, his last marriage was done at a court house and so was mine. Im 28 and he will be 32 so Im excited about planning a wedding and getting to have my day. When he and I started dating I informed him that I have PCOS and he was fine because he has 2 children with his ex wife, but that after we are married that we will go thu treatments together. We set our wedding date for April 30th because he said he thought it would be cool to get married on his birthday. I had asked him in the past when he and the kids mom had gotten married and he said he couldnt remember because they went to the court house and only gotten married because she was pregnant. My fiance and his ex wife share the same birthday also(april 30th) which is now my wedding date. Now we are down to 60 something days until we say I DO. Everything is paid for and planned out. I was cleaning over the weekend and found his divorce papers and noticed that they had gotten married April 29th..... the day before both if their birthdays.....so Im pretty sure they wanted to get married on April 30th but since they went to the court house it had to be April 29th. Now his ex and I can get along because we have too for the kids, but she is very jealous of me, and I have always felt that I am 2nd to her because my fiance and her have children together and his family still attends gatherings for hus exs family(even tho they say its just for the kids sake) . But now i feel like I dont even want to get married on tge date we set because I know as soon as his ex wife finds out the date she is going to feel like she still has one up on me. And I feel like dang man can I not just have something in this relationship that my fiance hasnt already shared with her..I mean they share kids, birthday, wedding date..... We live in the same house they had together, same furniture and everything.... and his ex makes sure I know that it was her house before mine...... so my question is...am I over reacting, getting cold feet, or is this something I should be upset about..... oh yea when I found his divorce papers I asked him about the date and he said oh I thought you already knew that.....