3 month old won't nap!

my 3 month old is a horrible sleeper overall! I used to be able to get into nap for about an hour and a half but only if I was rocking him the entire time in a rocking chair. it was absolute torture! recently he's only been napping for 20 to 35 minutes even if I was holding him. I decided that my knees could not handle the rocking chair anymore and that I was going to get him to nap in his bassinet. it's working for the most part but the Naps are still only about 25 minutes and he only takes about three of them a day. He's still pretty happy throughout the day but he's definitely yawning more and will only really go about an hour and a half between naps. I'm definitely trying to not be concerned and chalk it up to this little boy just being an awake baby