Missed periods

i have a 27 day cycle and got my last periods on 17th july 2015. v r ttc and had intercourse during my fertile period. According to my 27 days cycle i should be getting my periods by 13 or 14th of aug but i did not.i did a test 14th early morning and i got a faint positive line within the mentioned time frame of home pregnancy test kit. Next day morning a again got a little darker line within the time frame but its still faint line. i waited for 2 days n did a test again today. the line appears to be the same and not getting any darker. My breasts are tender and i get dizziness. m totally confused..m i pregnant or wat these faint bfp's mean....please help!!