Then you should expect your period to come at its normal time.
Yes, why not, but chances are they'll be flushed out with your flow and so you do not get maximum benefit from them. My obgyn told me to stop using them during my menstrual cycle and resume when my cycle ends. I think there's a practical reason for it.
Estrogen and progesterone, I think.
The hormone that is least active while you are ovulating is progesterone. Progesterone is built up and reaches its high peak before your menstrual cycle.
Progesterone looks to be more important for menstruation. You need fairly large dose of oestrogen in absence of the progesterone to maintain the menstrual cycle.
Progesterone and estrogen
progesterone
oestrogen and progesterone
There are two hormones that are responsible for the regulation of the menstrual cycle. They are called estrogen and progesterone.
progesterone secretion is at its highest
Progesterone
on the 30th day
Estrogens and Progesterone in the Ovaries