Bleeding and brown spotting

Hello mummies, last night i was bleeding on my panti liner. Then come brown spotting till today. Currently at my 14 weeks. Is it something i should be alarming? So far no cramp but just feel heavy at the lower abdominal and my waist is painful. Thought it will be normal for waist to be pain when you enter 2nd trimester. But the bleeding yesterday and brown spotting make me doubting it ?