advice please!!!

me and my husband have been TTC for 2 months now. last month AF came. this month hasn't. i had my period on 9/5/17 lasted 4 days. ovulation was the 15th. I was suppose to start yesterday. I document everything on glow. the last couple of days I had some cramps that would come and go, which were very light. usually before I start I'm in my bed in so much pain I can't bare it. I was sure my AF was coming last night because the cramps were lasting longer and back was aching. I woke up this morning and no AF and so far no cramps. I also started having a white creamy discharge. I'm feeling more wet down there than normal. keeping thinking my AF has arrived. I took a test yesterday BFN. any advice would help. thank you!!