Hi welcome to H.C.M.Forum. the drugs used for feflux disease may some times cause delayed periods, due to antispasmodic activity. dont worry if you stop the drugs you can get the period. or may not get for this month. other reasons are anaemia
pregnancy may be confirmed or excluded by home pregnancy urine test.
anaemia may be confirmed by simple Hb test in laboratory. for this i advise you to consult a physician .
as most of the hematinics are gastric irritants care must be taken & informed to the doctor about reflux disease. for g.e.r.d i advise you to stop taking spices, chillies, & junk foods. use core of curd with food.
for anaemia i advise you to eat green leafy vegetables, cearels, & fruits. don't worry every thing will be fine.