Late Period but a BFN Sunday night...

Looking for advice - my SO & I have only started TTC this cycle. I took a test on Sunday night (3 days before period was due) as I have a cough & wanted to take cough bottle. it was a BFN so have been taking it the last week. But, I still haven't gotten AF. I don't feel as though I have any symptoms either. I half feel like my breasts are tender but not massively. should I test again? And if it were positive have I made a big mistake by taking the Exputex?! feeling very worried about it. I came off the Pill 3 months ago & I guess my period could still be regulating itself. my cycle before the Pill was probably 33 days. Any advice/words of wisdom welcome! 😗