I don't know what it is, but I CAN NOT stay awake more than 4 hours at a time! And then I sleep for three hours, then up for 4, then back down for 3 hours. I feel like a grizzly bear hibernating for winter. I've turned my bedroom into a cave - dark, cozy and comfortable. I must have at least 8 pillow that I use just for myself. My husband starts out the night with 2 pillows, but I usually steal one more for myself during the night : ) I'm going to blame it on the Heparin injections I have to take now. I believe drowsiness is a side effect. But I actually have to plan my day based around my nap schedule. I get up with my husband at 7 a.m. and make breakfast, take care of Lenni LuLu (our puppy), and pick up around the house. He head's off to work around 8:30 a.m., and I take Lenni for a walk. Then I eat breakfast myself, watch the Today Show, and try to do some chores. By 11 a.m., I am exhausted. And not just a little sleepy either - I'm in full on Rip Van Winkle mode and can barely make it up the stairs and fall into my bed. I sleep until around 2-ish. Then I'm back up, walking Lenni again, and usually take on a project to keep me busy until it's time to make dinner. By 6 p.m., I start to get tired again and have to hang out on the couch like a sloth. Daniel gets home around 7, we eat, walk Lenni again, and then it's off to bed for this mama. Phew! I got tired just writing that out : ) Hope my energy returns by the time my baby girl arrives!!!!