Hi Tom,
Yes, very normal. Some guys do wake up just before they ejaculate. Others sleep through it, maybe waking up just after or not at all.
It's not at all unusual. Each man is built differently; some men sleep all through a wet dream and wake up to discover the sheets soaked; some wake up as they are ejaculating; and some, like you, wake up just before ejaculation occurs. In some ways, you may be really lucky - waking up before the dream reaches its wet status enables you to experience the feeling of the orgasm more fully. So, nothing to worry about. As a friendly suggestion, help keep your penis in prime health by regularly using a penis nutrient cream (health professionals recommend Man1 Man Oil). The optimal choice is a cream that contains L-arginine, an enzyme that helps create nitrous oxide.
It helps give you an erection.
Don't worry about it unless you have erectile dysfunction (ED).