It's but normal that when you pull the dip stick or open the oil cap of your engine while running idle may konting pressure at tatalsik ang oil. Compression test is the best way to determine if yung engine eh blowby na. Also check your air intake valves. If there's oil there then blowby ang engine. Here's a link that might help understand what blowby means:

http://www.bobistheoilguy.com/blowby.html