Hi Dr... I am 23 and was diagnosed with PCOS in 2012. I have been on metformin for the last 7 months and that has helped to regulate my cycles more. After sex yesterday morning, I had a pink mucus discharge. Later during the day I noticed that the discharge is brown. During the night I woke up with pain in my abdomen and this morning and the rest of the day I ve experienced lower back pain and some pain and discomfort in my abdomen. This would be very out of the ordinary for me, as my cycles are normally between 28 and 33 days and I am now on day 13 of my cycle and I ve never had spotting before. I am a bit worried as I am trying to get pregnant. Thanks you for your time.