Had my period 30th of july and next one came on 29th of august as expected, but as dark brown blood., for 3 days ,now red blood with clots 5 days aft?

Clots is a concern: While irregular periods are quite common (we see someone with a question about it at least hourly) none have clots and that implies something other than the usual periods that requires immediate (non-ambulance) attention. This is general advice and I cannot say in your particular case how serious, but it certainly is not usual situation.