It's been 7 days now since my hair transplant. Can I stop taking this propecia pill cause its effecting sexual drive?

You trusted your doctor for your surgery.  Your doctor gave you the medication.  Now you are having possible side effects.  You need to call your doctor, email your doctor, or see your doctor.  If you are having side effects, your doctor should know about it.  Your doctor can give you recommendations on what to do.  Propecia can give you sexual side effects.Other medications (such as the pain medications or sleep medications you are likely taking after surgery) can give you sexual side effects.

This is something you must discuss with your doctor. Propecia brings protection against shock loss after a hair transplant, but at what cost to your sex life. I often suggest that the patient reduce the medication, but you need to talk to the doctor about his assessment of your risk for shock hair loss. 

I would have to know more about your history to ascertain whether Finasteride is a cause of decrease of your sex drive. For example: 1. How long have you been taking Finasteride? 2. Do you have a history of sexual dysfunction? Also, you are in your hair transplant recover period and that may be affecting you as well. These are some of the things you should speak with your hair restoration doctor about.I have seen and treated about 2,000 men with Finasteride and the vast majority do not complain of sexual dysfunction. It has been shown in a very small percentage to reduce interest in sex for about a 6 week period but return to normal after 6 weeks. It does in fact raise circulating testosterone and reduces circulating DHT. If further interested read the link below from PubMed. But most importantly discuss this matter with your doctor. Finasteride will save and regrow hair in your crown area and without it you may lose a lot more hair.