What Causes Delayed Period And Frequent Urination?

Hi i am a 19 year old female, I had gotten a very light period last month , i thought it was implantation bleeding so i went to see the nurse and had a pregnancy test done, which came up negative. Im still waiting for my period they are somewhat irregular. I have no symptoms, but i have very frequent urination even when i haven t had anything to drink. Should i take another test? i haven t been sexually active since the last test i took.