wet dreams

I have been married to my wife for three years now. Okay naman kami at regular ang aming sexual intercourse na at least twice a week. Pero I still keep on getting wet dreams mga three to four times a year. Normal lang ba to kasi I feel embarrassed about it. Akala ko nung teenage years ko lang to naeexperience. Kulang ba ako sa sex? Paano ba ito matitigil?