soon to be mother in law doubts my pregnancy

I'm getting annoyed by my soon to be mother in law , her doubting my pregancy . I previously had a miscarriage  , besides myself and my doctor my fiancé know about my miscarriage . It  was really early and that's why we didn't choose to tell everyone about our pregancy . 
I was upset but since it was really early I didn't even know I was pregant so idk maybe that's why I didn't get too upset idk 
My heart goes out to all the mothers who've had misscariges while ttc. 
Now I'm pregant again
We waited a while to tell out friends and family . 
Once I told my soon to be mother in law she gave me a look like she was mad idk. 
I've tried my hardest to get to know her better and I've also taken care of her kids when she needed someone to watch over them. 
We had a cook out and she pulled my out to the side and was like oh so How many weeks are you? And asked me a lot of questions like doubting my pregancy. Last time watcher over her kids she was like so how many weeks are you again? And she was like .. You know you don't look pregant . You don't look pale . You don't show much. Have you felt anything yet? How many appointments have you had? Do you have morning sickness ? Tbh i was taken back that she would even make those comments that I "don't look pregnant" 
Just because other woman get get morning sickness you know some woman don't get morning sickness or I've heard others get it mid /late pregancy,,.. Or some just don't get it hard or don't get it. She's doubting me I can tell cuz she was like here lets have a beer .... 
You know not all woman show right away ... I'm really athletic and I have a small bump even though I'll be 5 months in a week. Since she we doubting me I honestly wanted to run to a pharmacy and buy a pregnancy test and pee on so she can believe me.... But instead I was really nice to her and asked her politely would you like to come to one of my appointments ? She didn't say anything I think she wasn't expecting that ... She put her beer down and was like no I don't have the time. I was like I can make it the latest apt of the day which is like 4:30 I believe and some days she doesn't work and she can take off ahead of time . She says her boss is fine with that isn't too strict about that. She didn't stay long she said she had to leave and quickly took the kids and left. It's really bothering me since she's always making little comments about my pregancy doubting it... It sucks and makes me upset . I havnt told my fiancé cuz it's his mom but I don't want to tell him everything and he'll think I'm talking baf about her. The only think I've told him was about asking her if she wanted to come along to my next appointment . But I havnt told him everything she keeps saying while we're alone never around him😕 i mean idk my fiancé told me he's not that close to his mom and its trying to get along with her and I don't want him to get upset buy that or say something and she'll start being mean to me just Beacse I've brought it up to him 😕 should I tell him? Or what would you tell her? I mean I've  taken vids on my apointmets and I've Showed her and my fiancé has also and showed it to his  friends he's excited ☺️which it makes me kinda forget all of that but it's always happens 😕😕