Husband doesn’t know if he came or not (TTC)

Been with my SO for 5 years and I’ve never witnessed him ejaculate. He’s healthy, and in late 20s. Sometimes there’s clear pre-cum minutes after we have sex never white or milky and he doesn’t feel it. He doesn’t have orgasms. It’s really frustrating because we are trying to conceive and the doctor told him that there is nothing wrong with him and that it is more mental. He never had sperm analysis. Is there any method to get him to ejaculate? It’s so frustrating and we’re afraid we can’t have children....