Is she gonna be upset?

My mom and I are super close...talk to her several times a day and see her twice a week...hubs and I decided to keep the baby a secret until Thanksgiving since I'll be 13 weeks. The reason we've decided to keep it a secret so long is we had a chemical in March plus our family has dealt with a lot of death recently...my stepdad, grandmother, and great grandmother all in 1.5 years...so, needless to say, my mom has had her fair share of grief. That is why we wanted to wait. Now I'm starting to feel like not telling her may have the reverse effect...it has gotten to the point where I'm lying to her to keep it from her...acting like I've gained weight...avoiding her. I know the rest of my family will be fine but my mom may feel deceived...wdyt?