Spotting

Hi, my husband and I have been ttc since June, when my iud was removed. We have two kids and were very lucky to get pregnant with them after a month or two of trying, so I assumed this go around would be no different... Not was I wrong! This is my first month in glow and I am hoping tracking my cycle will help. So, I've noticed very light spotting (light pink/ brownish) only noticeable when I wipe for the past 3-4 days. My cycle is supposed to start tomorrow, 11/30. Anyone experience this!?