When your period starts

Does it usually start with spotting, or come in full-force right away? Mine is being really cruel with me this month, last month I suddenly felt the strongest cramps EVER, and it started full-force within half an hour. It usually does start very soon after I feel cramps. I very rarely have any spotting. This month, I am 3 days before my expected period, and have been getting light period cramps for a couple of days, and noticed a bit of brown spotting after my husband and I had sex last night, and a bit of spotting after I wiped this morning. I am PRAYING that it is implantation, and not my period slowly sneaking in early😡. I haven't noticed any blood on my underwear yet. I am too scared to check with a tampon😭.