Hi SS, Welcome to HealthcareMagic Forum.
You haven't mentioned whether he used a condom or not? Anyways, you have had sex on the 26th day of your cycle and there are no chances of Pregnancy
as the ovulation happens around 14th day, if your cycles duration is 28 days. What you have been experiencing the Premenstrual syndrome
where in your Body is preparing for your next periods. Kindly don't worry as you don't have any chances of Conceiving.
Good Luck and Take Care.