When is it okay to announce?

I'm due September 17th this year. We had my 8 week appointment on Tuesday and everything looked great! Strong healthy heartbeat, growing right on track, we are low risk and the doctor had nothing but great things to say about our pregnancy and had no reason to believe it wouldn't go on to be full term. So we came home and told our grandparents, aunts, uncles and cousins and my dad the good news. We told some close friends also. We had to tell my aunt who owns a bar in our SMALL midwestern town (we have ONE stoplight in the entire county) and she's a big mouth. Literally the whole town will probably know even though we told her not to tell because that's just how she is. So my husband and I want to announce publicly this weekend so people can hear the surprise from us instead of through the grapevine and then when we announce at 12 weeks like we originally planned I'm afraid it will be "old news" because our secret will already have been out for a month. Is 9 weeks too early to announce? What should I do?