If you believe that you can get pure before leaving Makkah, make your Ihram from the plane and wait until you get pure and then have ghusul and go for Umrah.

You should make a condition while making your Ihram by saying: labbaika
allahumma umratan, fa in habasani habisun, fa mahilli Haithu habastani.

This means that if you were prevented from doing your Umrah due to something beyond your ability – like your menses- you can take off your Ihram without expiation.

I have 60 days old baby resident of Riyadh, i am in menses now(4th day).Im going on final exit from Riyadh back to my country next week so dont have time. Tomorrow having flight for Jeddah and return on Sunday back to riyd. I will be clean on Sunday, can I go for Umrah from there and where will be my meeqat to wear Ihram accompanying my Husband.