I have dealt with this problem 4 years back.
Theres a cute little trick i did that fix that problem.
I don't have this anymore.
but let me say; you may do better trying not
to have intercourse a few days in advance when
you are going start your period.
Go see a physician. That isn't normal and there could be something going on there
You need to wash properly in the morning and again before going to bed.