Is It Safe For Me To Take Susten 100mg For Period?

sir my lmp was on 9th may and still today I didn t get my periods. my breasts became swollen than regular but no tenderness or pain. on 1st of june some light brown bleeding happened for two days(not as regular period) my lower abdomen is cramping lightly, lower back pain occasionally . sometimes I am feeling dizzy, frequent urination. on 11th june I took hpt but it was negative, again on 15th june,it is also negative. today I met doctor she prescribed me susten 100 capsules to take orally. please tell me doctor, am I pregnant? should I take susten 100 now or not.