Pink Blood But Closed Cervix??

[Kay_]

This morning my BBT was 36.7C/98.0F and my cervix was medium-high, closed and medium-soft. Around noon I started experiencing very light AF cramps so I decided to check my cervix again, this time it was the same as before except I had pink discharge, nothing else, as if I was having a light period however it only would show when I checked my cervix..not yet enough to show on underwear. My cervix is still closed..so I'm confused about this being my period because normally it would be open and lower. Today I am on CD31 and 17DPO. Wondering what others think or if you've experienced something similar.

Past days BBT temperatures were:

5DPO - 36.5C
6DPO - 36.6C
7DPO - 36.5C
8DPO - 36.8C
9DPO - 36.5C
10DPO - 36.7C
11DPO - 36.7C
12DPO - 36.8C
13DPO - 36.8C
14DPO - 36.7C
15DPO - 36.9C
16DPO - 36.8C
17DPO - 36.7C

Thanks!