Weight gain

Chelsea • 22 years old , married in December, currently pregnant with out first

So I’m 19 weeks today and I feel like I’m not gaining weight as I should. This is my first time being pregnant and everything I see says I should have gained at least 5lbs and some say a lb a week but I started before pregnancy at 169 in first trimester lost and was down to 160 I then gained 4lbs but have no lost another 2 putting me back to 162.. should I be concerned or just thankful I’m not gaining as much?