Too soon?

I'm currently 9 weeks & though I'm still pretty early I don't feel comfortable working.....I work at a factory, Goodyear to be exact which involves me having to do a lot of pushing, pulling, & lifting....I just recently ( last night ) hurt my back because of this! Sense then I get spasms that shoot up my back! My job is pretty physical as rubber isn't the lightest thing to be pushing, pulling, & lifting! ( I'm having twins btw) I just worry about putting to much strain on my body especially because twin or multiples pregnancy isn't a walk in the park as is! But I'm afraid my doc won't see a reason to even suggest that I be let off on maternity leave or sna because I'm so early! I scheduled a emergency visit for tomorrow morning to see but what do you guys think? ( I work 12 hour shifts at night btw )