What Could Cause Heavy Periods With Brown And Light Spotting?

hi, i was wondering could you help me? i had what i taught was an implantation bleed 20th of march, it last 2.5 days, then i got my period 2nd of this month, it was heavy for 2 days and now its very light, normally i get brown spotting for 2-3 days then blood for 2 days and then light spotting for 2 days, i got alot of weird pains or twinges for the last 2 weeks and now im getting light pains, i never normally get pains and it a totally different period, do you think i could be pregnant or could there be another reason? thanks