the effect of USD strengthen would be insignificant against bitcoin, people don't sell bitcoin just because of a slight increase in the value of a currency, which is basically depreciating in the long-term, simply inevitable. The central bank could print money infinitely depends on the U.S. Federal Reserve decisions but the limited supply of bitcoin make sure its value will increase over time. However, the rise and fall of bitcoin value depend on the market demands at a certain period of time, especially in this year, if there are some corrections it's a normal thing as people want to take profits and withdraw their money.