I amn trying to find out what happened and keep my kids safe now dfs is investigating me?

my daughter came home two weeks ago with a sore on her bottom. it was scabed over and did not look to be infected. she gave many explaiations and dad gave none so i just kept an eye on it. she then came back this last weekend with the scab gone and said dad cut it off with a razor blade. i took her the next day to doc to have looked at since i was giving no explanation of what happened and was now really worried that he had cut it off like he was hiding something. doc hotlined as i was hoping.( previous false reports by x and was told another hotline between us would result in taking the kids) they would. now they are investigatin me? what do i do.