Fertile week

So last week my fertile week,was the 27th of Dec to Jan 2.. I went to go log my glow and check my calendar to see when AF was supposed to be here.. It says not that my fertile week was last week to this weekend.. And my AF has been pushed back a week.. There is a possibility that I am prego.. My boobs hurt so bad. Cnt drink coffee any more with out it making my nauseous and I'm craving certain foods and feel like I could sleep all day. So I'm am unsure what has happened... Any ideas?