Employers are not allowed to discriminate against individuals who are pregnant. However, as you are likely to be going on mat leave withing the next couple of months, it is unlikely that a company would offer you a position....... but thats not to say they won't. Obviously you wouldn't be entitield to any benefits, but if you wanted to return to work sooner than 26 weeks then you could discuss this with the employer.
I say you have nothing to loose so go for it!!
Lyndsey