I've been strictly vaping for 75 days now. All of a sudden, I cough sometimes when I vape? I understand that coughing is symptom of quitting smoking but does it generally start 2.5 months later?? I'm confused. This is messing with my good vaping experience! Any thoughts? Some details- I vape 12mg of nic, 70 VG 30 PG liquid, mostly fruity vapes and with my MVP2, iTaste VV/VW.