Usually, your period is normal and you have a normal sex life. If you have a delayed period, you should first check if you are pregnant. If you are pregnant and have vague pain in the lower abdomen, it is a common phenomenon, which is caused by the local congestion of the pelvic cavity after pregnancy, so just observe it. If you are 35 days pregnant, you can have a vaginal ultrasound, and if the pregnancy is normal, you will be able to see the gestational sac in the uterine cavity. If you are not pregnant and you have vague abdominal pain after your period, it may be a premenstrual symptom. Usually the pain disappears within a day after menstruation.