First signs of spotting

Anjil • 36 married 4 kids
Af was due 1/7/16 but received a positive test on 1/5/16. Today after shower and blow drying my hair I noticed some spotting?? I have no cramping ot pain. I'm hoping implantation... based in the apps I'm about 4w4d... This is my 4th baby not really worried at this point not sure. Any advice?