I experienced tightening and slight pain during my 2nd pregnancy. Sometimes for nothing I even feel sharp pain when i sit down or stand but i still continue to carry my back then 19mths toddler(boy) until i delivered. Now pp 3mths.
Probably i would suggest u nt to carry ur toddler for too long, like just carry her awhile and let her know you are uncomfortable get her to walk. Try not to carry her and walk for more than 10min. If experienced sharp pain, immediately put her down and sit down to rest. Don overstrained urself.
Happy pregnancy :)
U will miss the time with no1 while pregnant, though its very tiring and tough.