Wanting to get pregnant but no stable job

Hi everyone,
We're currently in round 3, I'm 35 years old, and we expect that getting pregnant won't happen overnight. I have a question about work and getting pregnant. I've received a 7-month contract, but it's project-based. It's possible that this project could end after 4 months. I work through an agency. Of course, my partner has a job, but I was wondering how things work regarding pregnancy rights in this situation. Do I build up rights with this, or is it heavily dependent on the number of months worked? Do I need to have worked for 6 months in this case? Despite all this, we've decided to start trying because I'm 35 and it's currently very difficult to find work.