Pink CM

This maybe TMI but I haven't gotten my period yet and it always come the weekend my boyfriend has drill always. I should've started my period on Saturday but I haven't yet. However, I have had the occasional one little streak of pink on toilet paper when I wipe after peeing and today I checked my cm and it was slightly tinged pink so I checked it again this evening and it is clear. I have very little/no cm. Usually before my period I get very horny and I'm not at all. I have gained some weight about 5lbs since my last period (I have been eating healthy/working out like normal). The only other thing out of the usual is having some gas which is unusual for me. My boyfriend asked me tonight if I am pregnant because I have gained a little bit of weight since my last period at the start of November. Anyone have any idea? Glow says I'm not supposed to get my period till this weekend which is different from my norm.