Need abit of advice...

I'm not looking to become pregnant, I have the paragard IUD and my SO and I are very careful. The last day for my previous period was on the 23rd of January and I spotted on the 5th and 14th of February. My period was meant to be here 3 days ago and I'm getting all my usual signs for it (Cramps, tender breasts, acne and bloating), but the red tide has not arrived! Because I get quite a late period anyway, I'm not sure if I should be worried or not? It is normally quite regular. My question is when should I take a pregnancy test from this point on? Like how many days, what time of the day etc...