miscarriage and heartbeats??

Is it true that it's very less likely for you to have a miscarriage after you hear the heartbeat? I'm 6 weeks and 1 day and we heard the heartbeat today and are wanting to do a Easter announcement but I'm scared I will miscarry again my miscarriage was at 5 weeks and 3 days a year ago and I do have a 4 year old son also:) plz comment