Greetings! Thanks for your query.
Treatment of pimples (acne ) depends on the severity and extent of problem. The initial phase is to control the symptoms (acne) followed by prevention and the last (but not least) is to treat the complications (pigmentation/ scarring).
Mild to moderate acne respond to topical treatment (creams/ lotions) usually containing "Retinoids"(if no contra indications) and antibiotics like Benzoyl peroxide/ Clinamycin etc.
Severe acne need oral medication like Tetraclines etc. and course needs to be continued for atleast 4-6 months. In suitable patients oral Retinoids can be used as third line therapy and it has one of the highest rates of success in treating acne problem. It is contraindicated in pregnancy due to risk of birth defects.
Please visit a Dermatologist for evaluation and treatment of your condition.
Please do not delay seeking expert opinion as it leads to delay in starting right treatment for you and also there is more risk of scarring due to acne.