It's okay to share, but there's a risk of miscarriage which usually happens in the first tri. So women wouldn't want to announce the happy news only to follow it up with a sad one. But it is definitely okay to share during the first month. You're happy and there's nothing wrong about sharing that happiness with others.
It's okay to share as it's good to let people around you to know you are pregnant so they can take extra precaution. Secondly, usually the first trimester are the most risky point of pregnancy as it's not stable yet. Thus many will wait till it's stable and confirmed before announcing.
It's ok to share, depending how comfortable you are about it. Some people don't coz the first trimester is usually the most unstable. Of course there's also the superstition that some babies are more pantang. Announcing the pregnancy a little too early can cause a miscarriage.
yup it is okay to share during the first month. most are cautious as there is a high risk of miscarriage. And also some of them prefer to keep it hush from family and in-laws.