Advice!

i hope its not to much info but i am in need of advice i am confused bc lots of people have been telling me different things tthe story is on march 22nd me and my husband used a condom and it broke and i was going to have my period a wk later but i got it 4 days later and it was very light pink practically  invisible the nxt 3 days and the the 4th day started heavy red into light and had alot of cramps usually my period goes heavy the very first 3 days then the last 2 days light but it is back at very light should i get a pregnanxy test? Could it be implantation bleeding?