What Should Cervix Mucus Look Like Before Period What Is This??? 37 Weeks 4 Days..is This My Mucus Plug...?

What is this??? 37 weeks 4 days..is this my mucus plug...? - what should cervix mucus look like before period

Just yesterday, the doctor told me that my neck was very broad and expanded, but she has not told me to add something. Then last night, my husband and I had sex, so I went into the bathroom and realized in the paper toliet ball too much discharge of dark blood welled up in her. I went back to bed and put a towel under me, and lose the discharge continues to be about 5 minutes, but more than their faces. Well, today I woke up and went into the bathroom again and its still there. It's something you see Dady or 2 before the beginning of the period. Could it be my mucus plug? Or how can that be?