 [ Symptoms ] my girl n i had protected sex late in the middle of her cycle last p was aug 8 or so could she be pregnant or missed p  4 days after sex she told me she had a little bit of spotting could it be inplantation spotting  we have always used protection [ Disease ] most helpful answer go see md asap my son had what we thought was a spider bite on his leg it did the same thing got very red and painful it ended up being mrsa had to get my son on antibiotics fast warm compresses will bring the puss up to the surface but the puss is very contagious mrsa is very common now but can be fatal do not wait better to be safe than sorry