Braxton hicks???

hi there! i am almost 23 weeks pg and today i have felt about 4 conractions. not painful but uncomfortable. i have a history of preterm labor. i lost twins at 21 weeks and i went into labor at 31 weeks with my 2nd child. they have me taking progesterone shots every weeks now to help with that. the contractions are not reagular...is it too early for me to have braxton hicks? should i be worried?