Can Lyme effect your menstrual cycle?

Well, having a heavier and longer period is more often just a symptom of having a uterus! Haha. Changes in the menstrual cycle can be effected by pretty much everything. So, yes, that would include Lyme disease. But any amount of stress can effect it, changes in exercise (usually exercising more means shorter and/or lighter periods), menstruation can bring on dietary sensitivities around that time, allergies can sometimes effect it.
While the "healthy" period is usually around the same time each month and is typically uncomfortable and a bit painful, the pain should be manageable. But, healthy periods are also subject to changes. Sometimes they're notably more painful, sometimes they come at different times, sometimes they're heavier or lighter-- none of which should be cause for alarm unless it continues and its heavy enough that she's having notable blood/anemic issues, or painful enough that it can't be remedied with a regular NSAID or she begins having painful urination and/or bowel movements more than during one cycle.

Depends on her age. I've been having problems for 15 yrs and just got diagnosed with Lyme. My periods got heavy and painful, then it skipped months and then got normal for a few months then it started getting heavy, etc. Finally at 40 it quit completely. That is early to go into menapause, maybe the Lyme has something to do with it.

Also my husband has it, so who gave it to who? Good luck and hope she doesn't have it.

I used to get horrible ovarian cysts that would burst 3-4 times a year!! The pain would send me to the ER. Since being treat for Lyme, I have not had any..... Many of my "female" problems have gone away as well.