Confused as ever! Help!

So Thursday night we did the BD and I went to the bathroom afterwards, there was brown/dark red discharge. I didn't think much of it until I went to work bc I continued to have light pink on toilet paper & small amount of brown discharge on panty liner throughout the day. It stopped last night at about 6pm. I had cramps at work yesterday and having cramps again this morning. AF is due in 2 days. I never had IB with my daughter so I'm confused if this is it or if my period is just being weird. If this was my period I would think it would have intensified by now but it stopped. Anyone have this happen to them just days before their period? Should I test? If so when? My birthday is tomorrow & was gonna go out for drinks with my fiancé tonight but now I'd feel guilty if this is true IB. 😔 trying not to get my hopes up bc I've wanted this for quite some time