Medical advice on headaches?

So I can't really find anything on google that explains why I'm experiencing and I mentioned it to my OB after I had my son but he didn't seem concerned and it went away and came back and it's worse this time. So say I'm asleep and I wake and I lay in bed and then I decide to get up. Or I have to get up during the night because my son is crying. Well I get up and everything is fine and maybe 2 minutes later I get this extremely painful headache that the pain comes in pulses and it literally feels like my brain is going to explode. But get this it only lasts like 2-3 seconds and then it's gone. And it only happens when I get up or stand up. I've had my blood sugar and blood pressure tested and they are fine. I weigh about 105 and I'm 5"1. Is any a medical professional that could give me some advice or has anyone experienced this?