9 month old nursing every half hour?!

My nine month old daughter suddenly wants to nurse every half hour or more... when I’m holding her, she just pulls my boob out, and when I’m not holding her, she crawls over to me and starts biting my shirt. At night, she won’t sleep without a boob in her mouth and wakes up crying as soon as it falls out. It’s been almost a week of her nursing for the most part of every hour, all day and night. Should I be concerned? Is this related to teething? Help!