Good Day Doc I've Been On Petogen Injection Since January

good day doc I've been on petogen injection since January this year , I missed my appointment that was on the 11nth of July, I haven't gotten my periods since until today, I've experience a lot of lower back pain and constipation and havyness on my womb lately so I thought I am pregnant .up until 2 test showed negative what could seem to be wrong with me plz help