I am experiencing an allergic reaction to Keflex antibiotic for the past 8 days now. Red spots all over my body and itching unbearably. Benedryl for 5 days did not work so now I am on methylprednisolone 4mg tablets starting 6 tablets on monday, 5 tablets tues, 4 tablets today etc. I'm on day 6 of my period and experiencing intense cramping in lower back, my chest feels tight and I'm bleeding very heavily. Is this Ok and I should just relax? or is something wrong. I'm still itching but it seems to be not as intense.