Period while pregnant?

Hello,

I was just wondering if anyone has had there "period" while pregnant. I'm as regular as can be, always follow the same pattern and flow. However, around five months ago (I had just started seeing my current partner) my period completely changed. Firer month it lasted for 3 days and I would classify it as scanty. Since then its increased but not nearly as heavy as it was before. Still regular and clot only change is the heaviness. Has anyone experienced this before. Their periods completely changing? Have had a blood test and hpt all negatives. The doctor won't do a hormonal panel check as my periods are still regular. Please help me ladies!!