TTC how do I take it easy when I have other kids

So I have a three year old and a one year old and me and my husband have decided to go one more time for our last child, how do I take care of myself during the TTC and early pregnancy stage if I’m constantly picking up toys holding my 1 year old etc? I’m scared I’m over doing myself I don’t want to miscarry because I was holding my 1 year old and had to bend down to pick something up. As soon as they are in bed I’m asleep too so I try and rest when I can. Any tips or suggestions for this busy mummy please lol thank you :)