Planning a trip to vietnam with friends

I am planning a trip to vietnam with my friends. It was initially supposed to be 10 days long but now I am thinking of adding 2 extra days to make it 12. Because i want to do the Ha Giang loop but i don't want it taking up half the trip.

This was my plan:

2 nights in Ho Chi Minh, 2 nights in Da Nang, 1 night in Hanoi, 3D2N for the Ha Giang Loop and then 2 nights in Hanoi again.

If i do end up adding the 2 extra days. 1. is it worth it? 2. what should i assign the extra days to