Having an unusual period?

My period usually lasts 4-5 days and usually starts out heavy.My cycles are usually between 23-27 days.This time for some reason i spotted on the 23rd after my husband and i had intercourse.I thought it brought on my period,but it stopped bleeding after a couple of drops.On the 28th i only had some pink discharge and only a little as well.on the 29th it was a little more but still very little and hardly any blood.I can't remember having a period like this in the past couple of years.I feel kinda strange overall.I took a pregnancy test a couple of days ago which came out negative though. But it was cheap and i took it during the day, not sure if that's why it was negative. Could it be stress too? My husband and i just moved back to the east coast from the west coast about 5 weeks ago.