question about symptoms.

i had sex about 12 days ago. 2 days ago i started spotting brownish blood (not even enough to fill a liner, and btw this has never happened before) then, this morning I began to bleed heavier with some mild cramping for a while(a couple hours) . now my bleeding has dwindled to light bleeding every now and then.i would lik to kno if you think this is deciduous bleeding (bc i had only a few clumps with light bleeding) i have had a continuous higher temperature for about 3 days now and have had headaches, constipation, and loss of apetite. i would just like to know if anyone else has experienced this with their pregnancy.thanx!