Should I be worried about a BM every 2wks to 1 month?

Hi. I had a quick question. I have been constipated for a very long time but just realized I was constipated if that makes any sense. I use to make fun of my husband for having a BM every day and then I realized that having a BM once every 2wks to 1 month is not normal (which is what I do) When I DO finally have a BM it is very painful, I have to strain, and when it finally comes out it is HUGE and sometimes has a white mucus around it. I also have been having a lot of lower back pain for the past cpl months and for the past cpl wks I have been getting a severe pain in my rectal area - like a sharp stabbing right where my hole is. My husband says something isnt right and I need to get it checked out ASAP. I had a BM this morning, and there was a dark bloody mucus when I wiped ... should I be worried? What is your advice?