Yes, hormones affect MS. There has been legit studies that back that idea. Don't ask me where they are, but I have read them before somewhere! My MS clinic nurse also said that they are a factor.

I also find that the week before my period my symptoms increase. It took me a really long time to figure that out. At the first sign of issues I check the calendar. It's kind of "nice" to know that is just P/MS and not a relapse.