i felt period pains as if i were getting it but nothing came - had pregnancy symptoms aswell

hi - im 40 years old - my last period was 10 sept and had intercourse on the 15th...my cycle is a 3 week cycle and normally very heavy.  on the 3rd of oct i felt period pains as if i were getting it but nothing came - had pregnancy symptoms aswell - mainly a very sore nipple and unusually moody.  i then spotted 2 weeks later on the 20th october, very lightly, for a few days and then it went away. i took a few hpts after that an they were negative but 2 got a line a few hours after the test. i then left it and thought i would wait till my next period. its now the time for my next period and on saturday night i spotted again with no normal flow. carried on spotting on sunday with a few cramps. today cramps are there slightly and there is a bit more blood but i still dont have to wear a pad or anything.  my tummy feels very heavy and bloated as if i should get a heavy period but then nothing happens.  could i be pregnant or is this normal for people?  ive never had a period like these 2 in all my life. i have one child already.