I seriously need advices

Im first time to join a discussion like this so please have patience hehe. so first, my last period was 2/25/16 to 3/2/16 i always have a 7-day period. my boyfriend and i had a protected (condom was used) sex last march 12 and march 19. march 12 was perfect, no broken condom happened, but last march 19, the condom broke, but no any signs of orgasm was there, it is still pure dry even if it was broken. my period was supposed to be 3/23/16, i got worried since it didnt came, but them it came last 3/27/16 and lasts until 4/2/16. i just got worried that maybe im preggy since it got late, i also had my latest period 4/23/16 to 4/30/16. now im still worried that "what if" im pregnant. but i hope not, i really hope not. i dont have any signs of pregnancy at all, no morning sickness, no tender and swollen breast (nope, i got this tender breast a week before my latest period come, is it normal? but thats all, after that i never feel any pain again), i started worrying when i get late period and worry again because i read about the breakthrough bleeding, i dont understand it all seriously.

so maybe you can cheer me up and have some advice for me? just for me to stop worrying that i may be pregnant. i am not yet ready to bear a child, after a "late period" last march i promise to my boyfriend that i will not have sex anymore until we reached the perfect age for us to be ready to be a parent.  

and is it normal to have an irregular cycle since i am in a regular cycle? do you get my point hehe. i get nervous on what will you response eh. my friend told me that maybe i got a late period due to stress in school because that time i had all the paper works to do and i almost forgot to eat a meal for almost a day or two.

i really appreciate your efforts in giving me some advice, thank you xx