Not getting periods from 2months.

Hello doc..I had unprotected sex with my boyfriend on 1st week of april n 9th April..i took ipill on 11th april n got my periods on 15th april..after that i again had unprotected sex with my boyfriend n now in may month i didnt get my periods..my date was 15th may whole may month i didnt get my periods i did test at home from ican it resulted negative..again 1week ago i had sex with my boyfriend but it was protected sex he used condom v wer in hope by having sex may b some blockage inside will get opened n i'll get my periods but unfortunately i didnt get by doing dis also..so i went to general doc on 28th may she gave me regestrone tablet n 2tablets from her own side i took it for 5dags still den m not getting my periods today again i did ican test it was negative..please help me out when will i get my periods m really stressed..is it serious that m not getting my periods or is it normal getting periods delayed its my 1st tym dat my period is delayed please help me out please..