HELP! How to tell my best friend I can't be her MOH due to pregnancy


So my friend is getting married next May, she has changed the date 2 other times due to COVID originally scheduled May 2020 then October 2020 and now May 2021, but I've recently found out in almost 7 weeks pregnant. This is a destination wedding in Jamaica and I won't be able to attend as the baby will be a newborn. I feel terrible about it and don't know when I should tell her?? Sooner or wait for the 12 weeks??... our families are being told this weekend about it.