What are the chances of me being pregnant? I m 18 years old and showing a good chunk of symptoms. I have lower back pain, constant urination, bigger appetite, gas/burping, constipation, mood swings, cramps,headaches, bloating, itching, nausea, my stomach feels full, and I feel like I could sleep all day. I know many of these are symptoms of starting your period, but I ve never had any symptoms before or during mine. Its too soon for me to take a test but I was just wondering how big my chances were.