Hi P.,
I have experienced the discomfort and slight spotting that it sounds like you are experiencing. I have one healthy child, I had a miscarriage and I have had an ectopic pregnancy. The pain was different in all three to me. Implantation can sometimes feel a little crampy and there can be a little spot of blood very early on. I had that when I became pregnant with my daughter. Just a little crampiness in my lower back...almost like my period was coming. My miscarriage started with no cramps and for a time of about 4 days, I had to wear a pad because I was having what was like a very light period. More than just a spot, but less than a regular period. On the 5th day or so, I had hellacious cramps and lost the baby at the emergency room. Ok..my next pregnancy started out fine as they usually do but then I started having radiating pain that would start in about the area of my hip and radiate down my leg to my thigh. I had no bleeding. After a few days, as the pain increased, I went to the emergency room and they said I was having "phantom pain" which can happen in pregnancy. ? I had never heard of that. My OBGYN got me in the next day or two and they took a baseline blood test. A few days later, he had me come in again and my levels had not increased quite enough, which is a bad sign. The next day I was in the emergency room again with intensified radiating pain and they again sent me home. A few days later I was in the doctors office again and they did an ultrasound and confirmed it was an ectopic pregnancy. I was in surgery the next day. My doctor told me that it was good that I had stayed on top of getting the proper diagnosis and treatment. SO..all of that to say, a little back crampiness can be normal and I wouldn't fret about just a spot of blood. If you have to start wearing a pad and have a few changes of that pad throughout the day, then you might want to just get a lot of couch and bedrest (the advice they gave me when I was in danger of miscarrying). If you have intense pain, go to the emergency room and don't wait for your doctor to fit you into their schedule. Once you go to the ER, somehow your doctor the next day will be able to fit you in. Hope that helps and maybe comforts you a little? Good luck! JPG