The very first sign is that you will miss a menstrual period. Your breasts will become tender and by 3 weeks, you'll have morning nausea. The quickest test that can be taken is the ones that are sold over the counter at your local pharmacy. The most accurate is the test that is actually done at a doctor's office.
You may experience signs like breast tenderness and nausea but the only way to verify or know for sure if you are pregnant is to take a pregnancy test.
Some of the signs that could be pregnant is breast tenderness, fatigue, a missed period, and cravings. Some people even experience more sweating and feeling of being hot a lot and mild leg cramps.