Miscarriage or early period?

I am 38 and have two children ages two and four. I have been trying to conceive this month and was very careful to have regular sex during my most fertile windows. 
At around day 20 of my cycle I begin to experience light cramping and a slight amount of blood, that I thought could be implantation bleeding. So I was excited that I could possibly be pregnant. 
However on day 22 I got what seemed like a regular period only the blood was more bright red than usual and I had more cramping than usual. 
My question is: was this early period (I  usually get my period on day 28 ) Or possibly a very early miscarriage? If anyone has any experience with this I would be very grateful if you shared. Thank you!