Hey pitterpatter
a chemical pregnancy is an early pregnancy that ends in miscarriage, really early, so early that there is no ultrasound to confirm that there was a pregnancy, only the raised hcg levels. That's why it's called chemical, it can only be confirmed chemically, the baby is too small to be seen on an ultrasound.
Since you're so far along you wouldn't fall into the category of chemical pregnancy, but it would be a good thing to get checked out by your doctor.
Here's a description I got of a site:
a chemical pregnancy is the clinical term for a pregnancy that is confirmed by a pregnancy test, but not by clinical signs, and is lost before clinical signs can be observed through means such as an ultrasound. The pregnancy test is often "faintly" positive or blood hcg levels are low. It is believed that fertilization occurs, but that the egg never implants.
And like in my case, hcg levels can be too low to register on an hpt. Hpt's need a hormone level of anywhere from 50 to 100...My levels didn't get past 29 or so.
I hope all turns out well for you