It's worrying when you notice blood in your cervical mucus. You expect to see it at your period time but not at other times.   In reality, it is usually nothing to worry about. Most women will have unusual bleeding at one time or another during their lifetime. Implantation bleeding is a common cause of bloody cervical mucus, and other reasons include ovulation bleeding and trauma to the cervix. 

What is Cervical Mucus?

Your body produces cervical mucus in response to your changing hormones. When ovulation approaches, your body produces more estrogen. This causes your cervix to produce mucus that is clear, slick, and stretchy.  You are most fertile when you see egg white consistency cervical mucus (EWCM). It helps protect the sperm and transport it safely through the vagina and cervix.  The fertile cervical mucus supports healthy sperm. It also helps filter out the unhealthy ones.  Your cervical fluid plays a crucial role in helping you to get pregnant.

Common Reasons For Blood in Your Cervical Mucus

• Leftover Menstrual Blood.   A common cause for the presence of a pink tint is old menstrual blood. Trapped old blood in the cervix can loosen. It can mix with cervical mucus and cause spotting when ovulation begins.
• Bleeding Due to Ovulation.   Some women experience ovulation bleeding. At ovulation, your egg will rupture from a follicle on your ovary. The follicle can release a small amount of blood when this happens.   This is quite common, and there is no need to worry.   
• Implantation Bleeding.  After the sperm fertilizes the egg, the egg then travels to the uterus. Once it arrives, it implants in the uterine wall.  Sometimes, a small amount of blood will be released, which is implantation bleeding. You may see it a sign of it between 6 - 12 days past ovulation (DPO).  If you do see bleeding around this time, it should only last a day or two. Keep in mind, not seeing implantation bleeding doesn't mean you are not pregnant. Implantation bleeding doesn't happen for every woman. Therefore, it is not a reliable sign of being pregnant.
• Cervical Trauma.   Trauma to your cervix is also a common cause of blood in your mucus.   It isn't as dramatic as it sounds. Intercourse or a small scratch from your nails can cause trauma.  It can cause light bleeding at non-period times.

 

Other Causes for Blood in Your Cervical Mucus

Most of the time, blood in your cervical mucus is not a significant issue.  If you have frequent or heavy spotting, then you should contact your doctor.  Several medical conditions can cause bleeding at odd times.  PCOS and endometriosis are two common conditions that can cause bleeding.   Your doctor will work with you to create a plan to find out what is going on.  The bleeding should be light and taper off after a day or two. If the bleeding gets heavier or will not stop, then you should contact your doctor.   Only your doctor can figure out the causes of non-period bleeding.

Sources:
https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/implantation-bleeding/faq-20058257
http://www.mayoclinic.org/symptoms/vaginal-bleeding/basics/causes/sym-20050756