When do your notify your company regarding your pregnancy?

After the first trimester usually. Approach your direct supervisor directly and let him or her know. If there are any special requests due to your pregnancy, you should let them know as well. At my old job, we worked shifts and it was quite a high risk job so mommys to be can request to be posted to only day shifts or office hours while they are pregnant (subject to availability of course). I would also take note of these mommys to be and assign them lighter tasks.