Look what i read in this link : https://www.murthy.com/2017/03/01/march-2017-visa-bulletin-check-in-explanations-and-predictions/
Family-Based Preference Categories
In the April 2017 Visa Bulletin, there may be “[a]ggressive forward movement in some of the family-based preference categories.” In particular, the family-based, first preference category (for the unmarried children, ages twenty-one and up, of U.S. citizens) has seen far fewer filings this year than expected. So, this category is likely to keep moving by several months each month for all countries, other than Mexico and the Philippines.
In the March bulletin it says the following in section D:
D. VISA AVAILABILITY IN THE COMING MONTHS
FAMILY-sponsored categories (potential monthly movement)
Worldwide dates:
F1: Up to several months
F2A: Up to one month
F2B: Up to five weeks
F3: Three or four weeks
F4: Two or three weeks
So let's keep our hopes up our category will be moving 3-4 weeks yay!!
