Adding another 2 bridesmaids- help!

My partner and I get married next summer and i asked two of my closest friends to be BMs a month or 2 ago…My partner has 3 in his bridal party.. I had thouhht on having 4 but it felt too much….. one of my BM has since fallen pregnant and is due on our wedding month so has had to pull out of BM duties… so the opportunity has now arisen that I could have 3 but I just don’t know how to go about it….. I have been asked to be a BM latterly and it never sit right, always felt a bit left out being asked late to the party… so I just don’t want to make my other friends feel like I did…. Half of me wants to throw caution to the wind and say it’s my day, go for it, I should have asked earlier, I didn’t, sorry.. but the other half says, I didn’t ask them in the first place… stick with that decision… ahh help!!