Blood tinge CM

Blood tinge CM 4 days before period. We have been ttc for about a year using a donor and self-insemination. In November I had a regular period. We did not get to try in December due to donor being out of town. I dont get blood tinge CM prior to period and trust me I have checked and looked for every symptom previous months. I haven't tested again due to period being so close and also thinking it's out of question due to period in November. I highly doubt it is anything but wish this will come true one day as well as for everyone else.