In my opinion this practice is not excessive, just under normal circumstances, the husband just more willing to take care of his people are you, rather than his mother, to put it bluntly: in some life care, you are more suitable, his mother care, if a little awkward.
Even if you say he was raised by his mom, and used to be taken care of by his mom when he was a kid, just after he grew up and had a sexual realization, your husband shouldn't even be able to sleep with your mother-in-law, right? And it's natural for him to feel a little awkward having his mother-in-law take care of him, and he wouldn't want his mom to take care of him. I understand that his idea is like this, as to whether or not you can talk to your husband frankly, between husband and wife should be honest with each other!
I myself have such a feeling, that is, after giving birth to a child, in the hospital for a few days, my mother-in-law is quite positive to stay in the hospital to take care of me, but I think her care to me is a capital embarrassment, I politely refused, at that time, my mother-in-law is considering not to let her son tired, would rather tired of their own, but I think that he, as a child's father, my husband in the hospital to take care of a few days is completely his own, I think it's a good thing that he is the father of the child. The hospital to take care of so many days is entirely his responsibility, and he is not made of tofu, it is difficult not to stay up a little bit will not fall apart.
But your first trimester of a special situation, I am quite able to appreciate that kind of tired, and the hospital that kind of bed sleeping with, genuinely sleep uncomfortable, not solid, and the hospital environment is not suitable for pregnant women to stay here for a long period of time, you can talk to your husband, both sides to find out a better way to solve the problem it!
You try to talk to your husband, that is, you shift system like to the hospital to take care of him, you get off work every day will regularly visit him, take care of some of his daily cleaning, and at night to accompany the night, you do not come, so that the father-in-law, mother-in-law to take turns to worry about, the two sides to talk about there will always be a way to solve the problem.