Moving houses/can my current landlord do this?

Cassity • Laila 05/15/17, Xander 4/10/18, and Grace 11/06/2019

I have a couple questions but first let me catch you up... I'm currently living in a trailer park with my husband and our 2 cats and 2 dogs. next week we're moving to our new house so im currently frantically packing. Right now my house is a mess because there's stuff everywhere due to the fact that I'm trying to get everything into boxes. Well yesterday my landlord called and asked if he could show the house to possible future tenants in a couple hours. I said no because the house is a mess and because he was giving me no notice at all. So he said that he's going to do it Thursday morning (tomorrow) instead so I need to make sure someone is here. I'm pretty young (19) and this is my first place so I've never had to deal with my landlord showing people the house while we're still in it. I feel totally uncomfortable with letting strangers tour my house with all of my stuff and everything still here and I especially hate that I have zero choice but to allow them in. I understand that he needs to get the house rented out asap but why can't he wait until next week to show the people our huse? When we're completely moved out? Idk I could be completely wrong in feeling this way because like I said I've never had to deal with my privacy being invaded like that. My new landlords won't let us move in any sooner either but they said since we're paid to the end of the month he shouldn't be trying to show the house while we're still here. Anyone have any idea about that? Am I just being ridiculous? And my second question is can I lift heavy boxes or should I just stick to the light stuff? I'm currently 12+1 and my husband says he will be lifting the heavy boxes but to be honest most of them are heavy and I don't want to feel like I'm not helping him. If I'm physically not allowed to because I'm pregnant then I won't feel so bad but I'm not sure. I don't wanna end up hurting my baby either.