Sleep.... Sort of Concerned!

So my baby boy will be 3 months ( 12 weeks) on the 18th. Lastnight, he slept all through he night. Went to bed and alseep by 9pm, slept all night till around 6am, i fed him and he went back to sleep from 6:20am, to about 8:30 when i eventually had to wake him up to feed him so i can go to work ( first day back today, and baby boy came with me to work )... I only worked one hour and went home at 10am. My son, cried the whole way home and i knew he would be tired becaues 10am is usualy when he takes his nap. He slept from around 10:30am to 2:30 in the afternoon, Was awake from 2:30 to about maybe 3:30 or 4:00pm, Went back to sleep during our feeding session, woke up around 6:30, fed him again, fell asleep again and now its 7:30pm. We usually have bath time at 7pm and get ready for bed and are asleep by 8 or 9pm.

 This is ALOT of sleep for him. He is usualy awake alot more during the day. He hasnt been this sleepy since he was a new born and i had to wake him up every 2 hours to feed him ( as per doctors orders).

 He usualy doesnt even sleep this much during a growth spurt.

I know that he has been teething, but no fever, and i had a cold the past 2 days, but i dont see any obvious symptoms of him being sick other than a few sneezes a day.( thought it might be allergies?)

Does anyone else have any advise or have gone through this around the 12 week mark? I'm a bit concerned that maybe he doesnt feel well and is trying to sleep it off or im not sure whats going on.