Just on the maternity leaver part, I don't think they have to hold your job for you if you have been there less than 12months....but most decent places will if you are good at what you do. But I think you still get paid something.

I've been in a job where someone took a new job at 10wks & didn't tell anyone til a month or so later & got paid leave and one of my closest friends took a job change just after getting married & got pg first go a month into working and got her 12wks paid leave also and the position was held for six months.