Implantation bleeding?

Hoping someone can help who may have had a similar experience (TIA!). My last period was on 1st Jan (after an unusually long cycle for me), and I only started spotting 5 days ago. Breasts are bigger and I've had some lower discomfort but nothing that's painful. Headaches for the last few days. I only notice the pink spotting when I go to the toilet and wipe. Sadly I don't know when I ovulated or if I even did (although since charting my temp from Jan there was a dip/spike so perhaps I did). Husband and I have not used contraception since the end of last year. Could this be a really delayed period or implantation bleeding? Abroad on holiday and can't take a test! Thank you!