If your too clean when your washing your vag in the shower you could be washing away the good bacteria that keeps yeast from taking over.
Same situation , you must have alot of bacteria also you and your husband could be passing it back & forth . Try not to eat too much sugar add yogurt with live cultures to your diet and let your privates air out here and there because yeast likes moisture .
My doctor said its common and I got it once so far.
same with me my doctor says its normal.
Its fairly common during pregnancy.