LHP also called lutenizing hormone(LH) is essential for ovulation which occurs every 14 th day of your cycle,only when ovulation occurs at the correct time you can become pregnant.
you have nt mentioned for how long you are prescribed regestrone
is it for 5 days or 21 or you are asked to continue?
are you bleeding?
regestrone is prescribed in your case i presume to aid ovulation as your LH levels are high and it would increase your chances of becoming pregnant