The more you know your body, the sooner you can feel something. Within a day or so of implantation you can feel your uterus harden and your tummy-area become tougher. You will also get a lot more thirsty and drink more fluids, then you pee more because you have drank more.
There are other signs as well... fortunately you have the "information super-highway" at your disposal.
Just rememeber that pregnancy cannot be diagnosed on symptoms alone. Most if not all pregnancy symptoms can also be symptoms of PMS, etc. A womans body can also seem to 'make up' symptoms if she is stressing about being pregnant. So even though you can feel symptoms as early as 2-3 weeks, the only things that really diagnose pregnancy are a missed period and a positive pregnancy test.
That is not exactly right either. Lots of women, especially young women miss periods. So one missed period, even two isn't a clear sign of pregnancy. And only a pregnancy test done by a health care provider would I trust to be absolutely true. Preganncy kits are almost always right if they are positive, but there are false positives.
You could have all the signs you are pregnant, have missed a period, and have taken an over the counter test that says you are pregnant and NOT BE pregnant. If that does happe you most likely have something wromng that needs atention from a doctor.
If you think you are pregnant - see adoctor to confirm ASAP. The sooner you know the sooner you can start making the best choices for yourself and your baby.
Have the pregnancy - get the support you need, start taking vitamins, eat well, follow doctors orders.
Adtoption -get the support you need, what kind of adoption? find an agency
End the pregnancy - get the support you need, find out what your options are