Can I eat more fish?

The recommended amount seem to be about two medium(well, not large)cans of fish per week(I know I know, tuna should be avoided as well as shark and some others. Acceptable ones are sardines-my favourite, herring, mackerel, salmon and few others).

Question is can I eat more than those two cans?

I was vegeterian for the most of my life till recently and red meat simply doesn't taste good to me even tho I'm not anemic I know that salad and peas won't quite do it as for ideal iron and protein intake in pregnancy so I was thinking could I just eat more fish?