Hello dear Understand your concern Pregnancy is not possible with protected intercourse. To become pregnant, full penetrative intercourse is required in the fertile period of cycle in which semen deposit in the vagina and fertilized the ovum. AS your partner used condom and did not ejaculate in the vagina, there is no possibility of pregnancy. Irregularity treatment depends on its cause like thyroid abnormality, PCOS, Hormonal imbalance etc. Gynecologist generally prescribed OCP, primolut N or gynacesoid but should be taken after proper evaluation after rule out the above causes. Hope this may help you Best regards Dr. Sagar