Persistant cough, should I worry?

I notice on the information sheet given with Tamoxifen…and I quote:

As with all medicines, undesirable events can sometimes be experienced…ie…inflammation of the lungs (which may present with the same symptoms as pneumonia, such as breathlessness and cough).

Well, I started with a cold about three weeks ago now, and it’s left me with this persistent productive cough, which I don’t seem to be able to shake off.
I don’t really feel ill, but I don’t actually feel well…if that makes sense.
I feel as though there is something in my chest and I have to keep coughing to get rid of it.
I don’t for one minute think I’ve got pneumonia, but I just wondered if it’s worth seeing the doctor as I’ve already had one set of Antibiotics, which just hasn’t cleared it at all, or will it go away on its own eventually?

Has anyone else had problems ?

Linda x

There has been a horrendous fluey cold around this year leaving a cough which my oncologist[yes I asked him!]says is taking up to 8 weeks to go.Mine is finally better after starting just after New Year.I had one course of antibx which helped but it came back.If its a productive cough its unlikely to be sinister I think.Good luckxx