Should I test?

I have PCOS, I’m on metformin 2 a day currently. I started Metformin about 7 weeks ago and have had no side effects (thank god!), my period came 3 weeks after I started it. I’m now CD 28. I haven’t really been tracking with OPK this month as I just wanted to see how I get on with the metformin before I start stressing.

Anyway, because I’ve never had a normal cycle I don’t know when my period is due. I’ve been feeling really sick the last week or so, been put off my food massively (not like me at all), get my appetite back and eat then feel sick again. Had some diarrhoea today. I don’t know if this is just late side effects of the metformin, normal for where I am potentially in my cycle, or whether I should test?