Is he working on his premolars? Did anything else change in the last couple weeks that might cause him to be waking early? I don't know much about BFing while pg, but I know that BM does change at certain points of pregnancy, so it's a possibility. You could check out this thread to get some support:
Pregnant and Breastfeeding/Tandem feeding Support Thread part 2. He likely is also in a developmental leap, as there's usually one not long after 1yr.
http://www.thewonderweeks.com/mental-leap-8/As for varying sleep needs, that is true, however as Anna has noted, your DS is quite low and OT is likely playing a part. At this age, if he's only getting 10hr at night, I would expect him to be getting at least 3hr day sleep over one or two naps. Here's a chart of average sleep needs based on a number of resources...
Typical Amounts of Day and Night Sleep. Regarding suggestions what to do, if he won't fall asleep for two naps at daycare, there might not be much you can do about it. Can you put him to sleep earlier for the night, so at least he's getting more night sleep and will eventually start making it to his nap time better, so getting better sleep overall?
Is he an independent sleeper at other times of the day? How are you doing PD?
(((Hugs))) and congratulations on your pregnancy!