Earliest you can tell what sex baby is from scan?

Andrea
We are getting married in less than a month and we wanted to do a gender reveal at the wedding since we'll have the whole family there.. I'm 14 weeks and 3 days. We go in for a scan on the 30th of this month.. Any chance we could find out the sex then ? 
Or when it would be easier ? To see if I make an appointment before the wedding to set the sex and go to the bakery and tell them what we would like 🙈