Hii Dr ..im 26 Yrs Old N 23 Weeks Pregnant...i

Hii dr ..im 26 yrs old n 23 weeks pregnant...i had to travel to my home country by air n its 4 hrs journey..i hav no complications scan normal..my dr has prescribed me proluton depot 500 ..is it safe for me as i hav no prblm...in 12 weeks i had anterior coverion os placenta but nw its normal , anterior...plzz ans my query as i hav to travel tomorrow