Is IB a myth?

I think I read too much! Especially since we've been TTC. I read a post where a doctor said IB is only a myth. The reason I'm asking is because today at 6dpo or 1 day past my fertile window I have a pinkish tint in my cm which is not normal for me, nor is it normal for me at ovulation. Of course the more I read, the clearer it becomes I'm either pregnant or dying! So, I'm asking what you guys think. Either way I'm taking precaution until AF appears. I also have been extremely tired and started having some kidney spasms (which I use to get a lot but not in a very long time.)