Dull cramps and spotting

I've been spotting lightly since my BFP on the 17th March but only yesterday did I start cramping a lot more. I went to ER twice and spent nearly half the day waiting only to be told not to worry. I need some reassurance, the cramping is about 5/10 on the pain scale, and the brown bleeding is continuous with backaches. It doesn't fill a pad but it's noticeable and always coming! Any of you have brown bleeding and cramps and deliver a healthy baby? I can't go through another MC, we tried so hard for this BFP. I just want to cry 😞