You should not try to change your period if it is not incredibly important, because this can affect the regularity of your period. The common side effects of Utovlan are mental depression, jaundice, headache, breast discomfort, dizziness, nausea and vomiting, breakthrough bleeding, changes in menstrual flow, amenorrhea, rash, melasma or cholasma, acne, urticaria, and insomnia. It is contraindicated during pregnancy as it causes side effects in baby. The most effective time to have sex is during your fertile window, which can last up to six days every month. You are most likely to conceive if you have sex one or two days before you ovulate. If you have a 28-day menstrual cycle, you re likely to ovulate around the middle of your cycle (day 14). If you have sex on day 12 – day 18, there are more chances of getting pregnant. Because you are going to suppress your period by Utovlan, you will not get pregnant unless you stop it and have a regular menstrual cycle. I hope this information will help you. I will be happy if you ask another question Thanks