Blood while coughing! Scared. Pollution?

I had tonsillitis and pharyngitis and due to which inwas on amoxclav 625 for 5 days. After 2 days, the inflammation in the throat region has reduced however today morning I when cleared my nose it had jelly like yellow mucus and also when i coughed the phlegm out from my chest, it was yellowish. So i kept on clearing the phlegms by coughing, and many times I got red blood tinged mucus. I am very much scared now. Please help me. And in the entire day i coughed but there was no blood but the phlegm was like stringy thick sometimes whitish foamy and sometimes clear. I am scared, please help me. Also I am travelling in prayagraj now, is that aggravating the condition/infection due to pollution? Please help!