In for medical examination, is it safe to smoke?

At the end of this month, I am in for a medical examination. There will probably be blood tests. It is not a drug testing, but I am not sure if it's safe for me to smoke pot or hash before this. I am not smoking on a regular basis. But if I smoke a joint, say, 3 or 2 weeks before, will they be able to tell, even if its not a THC test? Or will it affect the test results in any way? A couple of weeks ago I took a blood test, and I had smoked 3 weeks earlier. The doctor didn't say anything, so I assume the laboratory workers didn't discover it. However, as it looks as if I can expect several examinations and blood tests in the future, I feel a little uncertain if I should smoke at all while this is going on. If there's anyone out there who knows something about this, I would be very grateful for your advice!

I get blood work done a lot, I smoke daily, as well as other things ;)..I've never had anyone confront me about my drug usage or anything like that. No worries, hon. Smoke as much as you want. They have no reason to test your blood/urine for pot, so they don't. It costs lots of money and honestly, it's not their job.

Thank you so much! I didn't feel like abstaining from pot anyway, especially since I've only just discovered the stuff. I'm glad to hear it won't be necessary. Thanks again. :)

If your undergoing blood tests for some diagnostics to find a problem I would tell your doctor your an occassional smoker and if it might cause a problem with the tests.

I really don't want to tell my doctor. Yes, I know he can't tell anyone, but many people tend to have prejudices against marijuana users. And I'm worried my mother will find out somehow... I prefer not to tell anyone. And anyways, I smoke very little. Would it really make a difference, with the tests, I mean?