I am 44. My period was due on Feb 20, but has not come yet.

I have noticed the following: my aereolas are darker; my breasts feel fuller but not sore; I have a achy feel in my abdomen; I feel nauseous at times; I feel tired; last night I noticed a drop or two of what I think is colustrum on my nipples. How likely is it that I'm pregnant? Yes, I've been trying and not using any form of birth control.

Colostrum is typically produced during the second trimester of pregnancy. So, as early as 12-14 weeks.

At 44 weeks, you would most likely have a hard time conceiving and would be placed in the high risk category due to the many health issues that tend to arise in pregnancy at your age. If you are trying to conceive at this age, you should be in very close contact with your OB to prevent, or treat early, the associated risks of pregnancy at an advanced age.

With that said, there is no way we can even guess the likelihood of pregnancy via the internet. You will have to wait until you are two weeks late for your period, which it appears you are already close to that. Then you can take a pregnancy test using first morning urine. Until that time though, considering your age, it is imperative that you start taking a prenatal supplement (you can buy them over the counter) that contains folic acid. Treat yourself as if you are pregnant. Eat well, get plenty of rest, avoid alcohol, drugs and tobacco.