I'v Been Constipated For Months. Dr.said I Should Mira Lax

I'v been constipated for months. Dr.said I should Mira lax 1 capful & I tbsp. once a day. If this doesn't produce a stool take this solution 2x a day. Now I'm really constipated. clean myself out 3 days aga with 2 ducalax tabs.. Next I took 3 days, multiple doses of Mira lax each day. Nothing. getting small spirts of green, mucus slime. Should I worry