masturbation...

ok so im 9 weeks pregnant and my husband travels for work. hes usually gone anywhere from 24 for 90 days at a time, so i have 2 other children so i dont get to travel to see him as much i would like to because my oldest is autistic and car rides are not always pleasent... ok so anyways im just wondering if masturbation this early on is safe because we rely alot on phone sex to stay intimate. any and all input would be appreciated