how for sure a doc's preg test?

You could still be preg, your body may not be producing enough of the hormone to provide a accurate result. I blood test will be more accurate, and your doc can also do an ultrasound. If you are a couple months along then the fetus should be very obvious at this point...

The same as a store bought pregnancy test! The difference it the doctor confirms pregnancy and lets you know how far along you are and if things seem to be normal! They can also give you documentation for things like WIC and Medicaid! A test at home will not be adequate for aid! Good luck!

Edit: The negative test were most likely do to being done to soon! I had one negative and two positive before seeing the doctor!

There are many reasons why but some that I know of are hormone fluctuations, stress, cyst on ovaries, low thyroid, medication you may be taking. If you are still concerned with not having your period you can ask the doctor to do a Serum pregnancy test. That is where they draw blood and test it to see if you are pregnant. If that comes back negative then you are not pregnant and probably are having something else going on.

doctors tests are pretty acurate if it was a blood one, although after doing a few tests teh results still neg your prob not pregant thought theres probarly lots of other reasons you have not had your period, stress , wrong foods , other illness ask your doctor to be tested for something else or tell your dr your trying to concieve and how to go about it because you have not had a period there may be someting else needing looked at !

it's probably due to a hormonal imbalance. either your have to much or to little progesterone or estrogen that is causing you to miss your period. If you have gone 3 months with no period you need to call your doctor. two ways to fix it are a drug called provera which causes the lining of your uterus to shed without ovulating or birth control pills. both will fix it but one will not be good if your trying to have a baby.

Some reasons why a women may miss there period other then pregnancy are stress, extreme Weight loss, thyroid problems, not enough body fat on them. Many women athletes do not have regular periods because of their body fat being too low.

The reason it may have shown negative before, was because your hormones weren't high enough yet. I'd call your doctor and ask for another test.

Good luck.

maybe not. Take another preg test. if it's still neg. then consult your doctor about it. Its better to prevent incoming sickness/disease.