hottgyul wrote:yellowish and very productive, sensiman 
Unless you sniffing saffron, yellowish mucus is a sign of bacterial infection. It could have resulted from a possible mild flu infection.
Do NOT use products with cough suppressants example Tuscosed because the mucus will not move out as it should and the infection could get worse leading to bronchitis. If you get a fever lasting more than 3 days then you need antibiotics, if you do get do not just use it for a few days but follow the prescribed duration or else you will be promoting bacterial resistance.
I strongly suggest you get an non suppressing (no codeine, no DM which unfortunately means no "nice" feeling) cough expectorant like Buckley's original or a really good cheap on called BRO-ZEDEX and use it for at least 3 days.