Delivery room.

I only want my husband and my mom in the delivery room. I'm so worried someone else is going to come in. It's really stressing me out. My husband wants his mom in there and I'm just so uncomfortable with that. She can come in as soon as the baby is born and I'm covered up but while I'm delivering I'm so so so uncomfortable with her being in there. Are the nurses just going to let anyone in the room? Who do I talk too about who I want in the room? Like I said as soon as he is here and I'm able to have visitors she can come in. I just don't want anyone in there while I'm pushing and while I'm all exposed. I'm so uncomfortable with that. The only reason my mom is going to be in there is to talk me through it and honestly I wouldn't even want her in there if this wasn't my first baby. 
I want to add that he only said he wants her in there once and after I explained that I'm going to be very exposed and am uncomfortable with that he said he completely understood.