First time pregnant. What’s happening?!

Mrs

I was supposed to have my period on 27th May but tested UPT +ve with a faint line. Tested everyday afterwards but the line is not getting any darker. No major symptoms, only mild sensitive nipples. But yesterday I had mild cramping like my period was supposed to come and had tiny stringy brown discharge (pic 1) and this morning tested UPT -ve, had slow sex with my husband and few hours later, dry brown discharge again (pic 2) 😔 what’s happening?!