It must be written in my forehead

Yesterday my boss came to me and said we are going to have a big project starting soon. It's a motorway company, which is my speciality, and a big (money and work wise) project. He asked me if I wanted to be on the team.

Why would he ask me that? Of course I wanna be on the team. He never asked me that before, he just assumed. I said sure (trying not to sound to excited).

The he goes "you will probably have to travel to Poland...".

What? He never told me in advance I would have to travel, and I have travelled several times with other projects. Why would that be a problem? Because I might be pregnant? Well he doesn't know that. Does he? Is it written in my forehead? Will I not be able to keep this from people?

Of course now I am feeling guilty I said yes. I 'm afraid I won't be able to take this project until the end. M&A transactions can take over a year and if I have a baby in September he will be left with all the work.
If I can finish the financial model before the baby comes, he would only be left with the negotiation part, which is easier and more fun. And I really don't want to refuse this project over something that may or may not happen.

I guess for now I will say yes and after the u/s I'll tell him I'm pregnant and discuss this with him.

PS: I had another faint positive this morning, although with a less sensitive test. I have decided not to take anymore tests and just wait for the u/s. HPTs drive me crazy.