Talk to Gynecologist on Need Information

I have 3 year old daughter .i never missed my periods except when i was pregannet.i have almost 28 cycle .my periods was due in 5th march but from next day i feel pain in back like the periods is coming but there is just white discharge .strip test is negative but now from last 3 days i am feeling dizziness and something discomfort in pelvis and lower abdominal .Facing breathing problem from last 2 days .Please help me what should i do ? Is there is symptoms of preganncy?