I Have A B12 Deficiency I Have Injections Every 10

I have a B12 deficiency I have injections every 10 weeks and have done for the last 5 years. I am trying to conceive a baby, will it have an impact on this, or is there anything I need to worry about once I am pregnant?

Also how long should I take folic acid tablets for? I have now been trying for 7 months and taking supplements on and off for this time too.