Hello,
Welcome to ehealthforum and thanks for writing
It seems you are having premenstrual symptoms.After the menopause it may take few months for the hormones to regress.Usually until the periods are completely absent for a period of one year it is not advisable to have unprotected intercourse as pregnancy can occur.
Since it has been just 3 months when you had last periods it is advisable to use protection for sometime until the cycles are completely stopped.
Take care!