Is this mean?

My husband and I got married in July 2016. Literally, ever since the day after, my mother in law has been asking if I was pregnant. Mind you, at that point I was still on birth control. The first couple months after being married we just wanted to take last minute trips, drink and basically just enjoy being married. The question didn't bother me the first couple of times but by the hundredth I was annoyed. One. It's a personal subject. Two. I WAS STILL ON BIRTH CONTROL. Three. We had told my mother in law we were waiting a year (to get her off our backs) but she would STILL talk about it every day. I had explained to her that I was frustrated with her constantly talking about it and she toned it down a bit. So here we are, I am now 4w3days pregnant and so excited! The thing is I really want to share this with our parents but we do not want anyone else to know. The problem with that is that my mother in law is so attached to Facebook and into drama that we know she will tell everyone. And when I say everyone I mean everyone. Is it mean to just tell my parents for now? Another thing I am worried about is my MIL and I work out at the same gym. I am assuming I am going to have to tell my trainer I am pregnant to modify my work outs so I don't want my MIL to find out before my mother.