Re: EC regression...what do to?
Similar things happened with several of my kids. For the most part, you just have to go with the flow. Some kids are very sensitive to wetness and soil; others seem as if they couldn't care less, even if they've been ec'd from birth. In my experience, the EC journey will have ups and downs. You could have a kid who has very few misses at an early age; then a month or two later, he goes through a "potty pause" and refuses anything to do with the potty. None of my kids had a simple progression from using a diaper all the time to fewer and fewer misses to graduation. It was up and down, up and down, often with breakthroughs right when it seemed we weren't going anywhere.
I do try various things get out of a potty pause by changing something in my EC routine. I don't force, but I do whatever I can to get just one catch. I might try nursing while offering the potty to relax the baby and get him to go. I might use a new potty or offer in a new location or a new position. I might put my baby on the potty and read to him until he eventually goes. I found that I could often get over a hump like this with a single catch or a couple catches. The success is self-reinforcing. Concentrated effort and creative thinking often yields results, but don't drive yourself nuts. If it gets too annoying, take a break and come back to it fresh later. I've done that, too.