Overbearing Moms

Di • 32 - first baby due June 14, 2015
If any of you have overbearing mothers like I do, how do you keep yourselves from getting stressed out by her? 
I haven't even told my mom I'm pregnant yet (trying to hide it) because I don't trust she'll keep it a secret, but she's also super bossy and overbearing and I find myself feeling stressed around her already. It won't be a good pregnancy if this keeps up.
Tips would be welcome!