Could Vaginal Bleeding And Lower Back Pain Be A Sign Of Miscarriage?

I'm irregular and I haven't had my period for two months. The first time we did in a long time with my boyfriend was 6 weeks ago. I usually get my period by at least end of the month or sometimes the 18th of the month, so I thought I was pregnant, but pht showed negative last Thursday. Last night I fell from the bed. Today, when I woke up my lower back hurted badly, but didn't get any bleeding, but lately sometimes I get mucus/ jelly discharge on my underwear I thought I should wear pads. So I did, and when I went to the bathroom to pee I saw a blood (very light red-more like pink) with mucus discharge on my pad with my lower back still hurting and I feel like throwing up. Is this a sign of miscarriage or is this just a very late period. When I wiped there was no signs of blood even on my pee just a pinkish color and jelly/mucus on the pad. Please help.