Havent announced pregnancy.. SIL did on FB

So we still haven't told some family memebers, friends or coworkers about pregnancy. Husband and I went to a baseball game. I posted a picture on Facebook. SIL comments "SHOW US THE BELLY!!!"... people start commenting OMG I didn't know you were pregnant ?! I knew you looked different!!! Holy crap you're pregnant? We truly didn't want to announce it that way so I deleted all pregnancy related comments. Is that bad/rude of me to do that?