Bridesmaid and Pregnant

My best friend asked me to be her bridesmaid over 12 months ago. I just found out I am pregnant with baby #2 and will be roughly 7 months along for the big day. I am nervous about telling her because I don't want her to feel like I've ruined her day. She's had a few things happen recently which haven't been what she's planned for her big day, so I've held off telling her until 'the time is right'. Should I trust she'll be happy with my news or have I put another link in her day?