Two months ago I started a 6-month long contract-to-hire job and just noticed I am pregnant. They like me and everything works out so far. First question: When should I tell them ? My concern is that they will not hire me.I know it's illegal to not hire someone because of pregnancy but they can come up with any other excuse. How probable is my concern?
I would talk to them sooner rather than later - they will eventually find out about your pregnancy.
You are basically going to get one of two reactions:
1) They are negative towards the situation - you now have more time to prepare yourself for the end of the contract and figure out your next step.
2) They are positive towards the situation - you now have nothing to worry about (and saved yourself some stress). Hopefully, they will be supportive and have a variety of options/solutions available to you.
This kind of approach pretty much applies to any situation where there is potential for medium/long-term absence from or disruption to work.
Following your comment above - be sure to explain that as your plan to them when talking to your supervisor/manager/company.
It will be in their interest to hold on to you even with a break, since replacing you will require advertising the position, interviewing, selecting, and training a new person. Having you absent or part-time for a period after the birth should have a much lower impact on their business.
First of all, you should probably start looking at other jobs right about now.
Considering that pregnancy shows at a certain point, you do not have the chance of keeping it entirely secret from them.
After you have something lined up, you should tell them. Be prepared to be fired or not hired after this.