Can someone give me a little advise

Hi, well I'm four days late on my period I took 3 tests  and one of them have a really light faint line on it and the others came up negative, could I be pregnant? and should I take another test in a couple days? 
I've not had no signs of my period, but have been getting lower pains in my left hand side and the ends of my nipples are getting sore but going a darker colour what shall I do? Also I could cry all time😭😭?!?!