What Causes Sore Breasts, Drowsiness And Spotting Between Periods?

for the last week or so i have had sore boobs and sleeping alot :( i had a preiod in the begininng of novmeber and a bit of spotting at the end and i have done a pregnancy test and it was negative so i done one with a docter and it was also negative but the been waking up wanting food :( cud this be a sign of pregnant the docter reckoned i cud be ??? can u help