I've come to US on a B1/B2 visa and it will expire in mid June. There is a company that is willing to sponsor me for H1B. Since there is about a month left of my current visa, Do I have to extend my current visa and then apply for change of status? What if I can put everything together and file for change of status before my current visa expires (My LCA is already filed to DOL)? If that's the case then Can I remain in US while my case is pending or I have to stay in status?