What Causes Spots With Yellow Tips At The Head Of The Penis?

I had unprotected sex with my girlfriend about a month ago and just recently in the past 5 days or so, ive realise a few spots on the base of my penis. Im wondering what they might be? They are about 3 - 5mm in diametre and there are about 4 spots. They look asif they have a white/yellow head. I thought they were teenage spots you get on your face and I popped them and yellow puss came out? Are they regular teenage spots, going through puberity. Also i shaved my pubic hair off about 2 weeks ago as a dare to show how much i loved my girlfriend. Is it a shaving rahs maybe