MY HUSBAND DOESNT UNDERSTAND WHEN I TELL HIM NO ABOUT SEX BUT IT'S REALLY PAINFUL FOR ME IS THIS NORMAL
Oh boy, sex and MS. This is a huge topic, in fact I wrote about six posts on it last spring. You can start reading with the first one - Sexual Dysfunction and Multiple Sclerosis. In answer to your question, yes this can be normal (although not everybody with MS may experience painful sex).
After you have read the entire series of posts (begun above), perhaps you can have your husband read the posts as well. This might be the easiest way for him to gain a better understanding of how our MS bodies react in different situations.
I'm so sorry that your having these problems right now (I've been there!!), but hopefully it is one of those fleeting MS symptoms which goes away on its own.
But definitely, mention this to your neurologist even if he/she doesn't ask. It is an important part of life and your doctor may have some suggestions for you regarding treatment or technique.