I have taken 4 pregnancy test. All come out negative but I have missed my period for 10 days now and they are always on time. I was pregnant 2 years ago but had a miscarriage. That time I was told by doctors I wasn't pregnant that I was probably just stressed which was causing me to miss my period so I believed them. After they told me that about 2 weeks later I was bleeding went to the hospital and they said it was a miscarriage. So now I am thinking could I be pregnant again? If so what is causing my test to come out negative? Help please!

Usually, despite the advertising of HPT's, 10 days is too early to get an accurate result.

You will probably need to wait until you miss your next scheduled period and then try testing. Be sure to follow directions exactly.

While many women do get a positive result early on, not every one does. It will depend greatly on the when you ovulate, when implantation occurs, and how sensitive the test you use is (they can vary in the level of hcg that is measured). If you happened to have a later than average ovulation and/or implantation that occurred on the later part of the norm, it could account for a pregnancy not showing up yet.

Of course, it is also possible that you are not pregnant and your cycle is just off; which can happen for a variety of reasons. Wait another week and see if your period shows up late. If not, either try another home test or see your doctor about having a blood test done.

Will agree, in many cases you will need to be at least 14 days late to start your testing, so I agree, you are testing too early.
Also you need to be doing the test, first thing in the morning, with the first urine of the day for best results. Some women may even go into 2nd month and not show positive on home tests. So in one week, if still negative results, you can try a blood test.