18 month old has had a cold for over 2 weeks?

My 18 month old started showing symptoms of a cold on October 16th (I remember the date specifically because it’s the day my best friend got married). The runny nose & cough got bad on day 3. The snot got super thick & was making it difficult for him to sleep. Used Zarbee’s cough + mucus & it seemed to help. Cough stopped on day 7 & the runny nose seemed to be calming down. Day 8-10 he still had the runny nose but it was barely bothering him. Day 11 snot super thick & was pouring out of him like a faucet. Now we’re on day 18 & the mucus has thinned out again but his nose is still running like crazy. Cough never came back.

I don’t think my oldest ever had a cold this long… he had RSV back in August & it really affected his breathing (so much so that he went into respiratory distress & had to take him to the ER), but that seemed different compared to this.

Is it normal to have a cold this long? Should I make an appointment with his pediatrician?