My boyfriend is attening a bachlor party. That's fine but I'm 7months pregnant and I want to stay at home and sleep. He is persistantly suggesting that I don't come home that night because they are going to be at our house should I be worried

Do you trust him? If so, than don't worry.

Sounds like he's just planning ahead, knows they'll want to party late, and they'll probably be drinking, so crashing at your house is a good idea. He doesn't want you to be disturbed by a bunch of loud drunken guys, that's why he's suggesting you go somewhere else that night.

Don't worry. Maybe make arrangements to go to a friends house, have a girls night of sappy movies, manicures, eating junk food, and gossiping. :)

Each should do what they feel is best, rather than let society force you.. if you want to stay at home and rest, then that's fine. If he wants to attend a bachelor party, that's fine too.. though concern is understandable.

Evaluate closely and decide if you trust him enough for him to attend the party... - I'm sure things will end up all right, right.. And if you continue having doubts, no matter what, you can always have a talk with him - not to persuade him out of it, but simply to express your feelings.

So, he's not only attending the party, but he's hosting it as well.

You want to stay home and sleep, but, that isn't likely to happen.

I don't see what the big deal is for you to go and sleep at your parents' place, or a friends place, or even rent yourself a hotel room for the night.

I don't know what you are worried about, other than most likely a mess.

If you trust him, then allow it.

Look at it this way. He is coming home. I see this as him looking out for you, because a bachelors party is most likely going to get loud, drunk guys, messy etc.. None of that, especially while being pregnant is something you want to hear while you are trying to sleep. I agree with Altenweg, do a girls night thing. Don't worry unless he gives you an actual reason to worry.

Here is a great opportunity to show your boyfriend that you know how to handle a mature relationship. By giving him this time to host a buddies bachelor party you are showing him that you have the up most trust in him.
By going somewhere else to rest and not bashing him about this might work for you in the long run. By showing class, you are impressing him for possible moving forward with your relationship!!

Sounds like he should have talked to you before he decided to use both your and his home for a party that was adult in nature.

So your choice to stay and perhaps stay in other room while there is what ever entertainment they are having, and perhaps drunk guys making rude jokes and the such.
Personally his request is not really out of line, perhaps he will pay for you a elegant hotel and spa stay that evening