I was going to work this morning. I was entering a four lane on ramp into downtown. The on ramp combines two lanes from the freeway and two from other areas. I was originally in the number 3 lane, and needed to get into the number 2 lane - as I do every single day. Traffic was a bit heavier today so it was moving very slow. I noticed that no one was in the number 2 lane, so I threw on my blinker and merged behind a red car and came to a stop. A Ford Expedition that was in the number 1 lane then merged into my lane and side swiped the back corner of the driver's side of my car. I had my blinker on when I merged. I did not cut anyone off. She clearly was not traveling at a safe distance or she wouldn't have hit me. I called her insurance and filed a claim - and then she filed one with my insurance. How can I be at fault??

YOU can be at fault if she says you moved into her lane and hit her.
Then the courts will have to decide who is at fault. Or they may decide each has some fault and may assign a percentage fault.

Was the police called ? Was there a police report and did they claim someone at fault.