Visa stamping on 2nd H1 B approved petition


I have 2 H1 B petitions approved in 2013 from 2 different employers A and B.

I am in India. I have attended the visa interivew with company A approved’s in pending with 221g. its been more than 3 months and no decision yet.

1Q. Now, can i go for another visa interview with company B approved petiotion while company A petition is pending?

2.Q or Do i need to wait for the decision on first interview. If the first one gets denied, then can I go for the interview on 2nd petition from company B?

3Q. Will there be any questions in the interview about the first petiotion ?

4Q. is there minimum period i should wait for before I attend the second interview?

Thank you for your response.