5-6dpo

So I am currently 5-6dpo. I O'd on cd12&13. I got 4 very dark opks during those days. Hubby and I had already been dtd every other day since cd5. So on cd16 (3-4dpo) I had light cramping in lower abdominal area. Nothing much really. Just enough to notice. On cd17 I had dull achey cramps in the same general are but more in my uterus than anything. And today cd18 I have had some slight cramping. I went to the bathroom and when I wiped I had pink cm. It didnt last long and was only there when I wipe. Could this iB?