Faint lines?? I'm scared to believe it!!

I'm on CD51, although I vary from 40 a 48 so very irregular, my husband and I have been trying for 16 moths, I have done 2 previous tests on CD45 and CD50 they were both BFN, my breasts are unbelievably sore.   wanted to check again as I have a party to attend tonight and obviously  wouldn't want to drink if I was pregnant. I've done a dip test and got a Faint line so I tried a better test and also got a faint line??? I want this so badly but am scared to get my hopes up, please some advise would be great ???