Why is my body doing this to me? This is so weird! Please read and see if you have an explanation for me. TTC!?

Past few weeks - awful headaches, little nausea (didnt get sick with my 1st baby at all) cramping, dizziness, small sharp twinges in lower right lower tummy. I have been feeling totally weird for these past 3 weeks, not me at all. BUT I started my cycle the 17th, it is ALWAYS regular and ALWAYS 5 days... well today is day 3 and it is gone, just a little brown egg white stuff. I do not know what this all means. I have been TTC for 6 months now. Can someone please give me some advice... Is it possible to still be pregnant? Thank you. :)