H1B Amendment - Does end date change or extends?

Hi, My employer has filed H1B Amendment for location change with USCIS in regular mode in Jan 17. I’m outside US currently. My petition end date on original approved petition is May 30, 2017. Its been over 2 months and I did not receive any update on my case. Is it possible my end date will be extended if Amendment gets approved? I’m curious now as time when the Amendment will be approved my original end date would be close to expiry and need atleast 3-4 weeks for stamping thereafter, although new LCA attached supports end date of May 2018. Kindly respond if anybody went through similar situation. Thanks in advance.