Three times in three days

Monday I was headed to Wal-Mart, I was just to the Post office (Some one may know the area I'm talking about so I'm being semi specific) on F street and I heard an ambulance siren behind me - I went through intersection on 6th street then pulled over... it passed me and kept going. Tues. I was in the same place but a bit further on F and headed up 7th. I turned on 7th didn't stop and pull over because the Ambulance was a ways away and had no clue which way it was going... It ended up turning on to 7th behind me, I pulled over and it went on it's way. At this point I thought it was a bit odd that this happened two days in a row. Well... as by the title - it happened again today. Was headed towards Wal-Mart again. Although this time I pulled over before it passed 6th street. All this makes me think I should see if someone is following me. :)

(For clarification and my defense, I did not block the ambulance I pulled over before it got close to me.)