Sacked on 1st day for being pregnant

So I'm new to Tauranga and just got a new job, but on the 1st day I was honest with them and told them that I'm pregnant and was told that wasn't going to work out with them. The problem is they wanted to train me up to take over when their manager goes on maternity leave, which would be about 1 month before me. I know there's discrimination laws etc., but I don't want to work for someone who is going to be disgruntled for the next 6 months. They did say I could come back next year if there's a position available as they really wanted me for the job and I was their top pick by a long way.

Problem is, what to do now? I really need a job, babies aren't cheap! Do I try and find a job in a large company so that maybe it wouldn't be such a problem? I'd also really like to qualify for maternity leave, so need a job asap as baby is due in Oct.

Feeling frustrated so any suggestions welcome?
Thanks!

No it wasn't advertised as maternity leave, just as full-time. I totally understand where they are coming from and therefore don't blame them, but at the same time we really need some $$$ coming in. I was excited by the job because it was going to be interesting and a challenge, but timing just sucks. I think I'm going to have to try and find something in retail/big company, where they would already have a high turnover of staff.

Thanks for reply though Nellennium :)

Hi Dolly, thanks for your reply. I was just about to sign the contract, but one of the points said I had to declare any "medical conditions". I decided honesty was the best policy...ha! But I honestly don't think it would have been a problem if it wasn't for the fact that our maternity leave dates would clash. Just poor timing.

Time to lick my wounds and find something else, it's just hard to know what/where to apply for so that i don't end up in the same situation again.