Around here the bridegroom is the groom for around the same period as the bride is a bride. You don't hear this often because guys don't talk about weddings as much as girls (running off to hide for a while after I post this).
Looking into the past via the OED, bride has a very long history, but the original word for the other half of the wedding pair was gome, a mane, hence something that would have looked like bridegome.
The more astute reader will have noticed the vague resemblance of gome to latin variants on homo and indeed original versions of gome include gomo, gumo (and others). As for pronunciation, I fear that there is no one around who remembers how this was pronounced 800 years ago.
More recently, the word gome faded from use and around the 16th century bridegome dropped the gome and adopted groom - a lad, a man-child, a man OR alternatively, the term bridegome faded and the pre-existing term bridegroom took over.
Somewhere in this forum is a discussion about groom, and how groom shifted from the above general meaning through a term for any male servant then a servant who cared for animals to become a carer of horses.
Bride used to be unisex
The wedding pair were the bridewoman and the brideman (or the 14th century equivalents)
Much of the above dredged from the byways of the OED.
Speaking of homo-gomo-and groom, my daughter in law is a horse groom. She tends horses, walking them, brushing them, exercising them and feeding them. Although she was a bride and a groom at the same time, she wasn't a homo.
Groom would have, in my vocabularly, an even shorter life-span in relation to a particular couple than bride would. There would never been any reference to a "groom-to-be" in advance, and the post-wedding use of the word would only last a day or two at best.