when do i call my ex??

Ah
im due in 7 weeks and my and ex and i live 2 hours away from eachother. im wondering when i should tell him im in labor (obviously when im in labor) but im a ftm and have no idea how long things will take or if i'd even know if i was in labor or not and i'd feel terrible if he drove all the way here for a false alarm. should i give it an hour or 2 to make sure its the real deal or call him right away? im due christmas eve 🙄 so the roads may be bad and it could potentially be christmas day when i deliver. i really would hate to have him rush here on christmas and then have to wait a full day before baby comes.