I'm so confused. Please read. Sorry for it being so long.

I got a copper IUD Dec. 6 but it didn't mess with my period I've been tracking it for 3 or 4 years and it's barely changed over that time. My last period was on Jan.7-11 which is a pretty normal period for me being 5 days. Me and my guy had sex on the 23rd which is a day later than my calendar said I O'd but I've been spotting light pink and brownish almost everyday since the 25th very very lightly mostly just when I wipe it's such a small amount as in there's not even enough to need a pantiliner but I've been wearing one anyway to kind of keep track of how much it is. February 5th-

6th I did have darker red almost mucousy looking translucent almost blood but still it was just like a lighter period not even filling a light pad all day and it went back to spotting. I've tried internet cheapies and first response and I either don't have enough hcg or I'm not pregnant because I think I see a line on some of them but not all of them. I would be 4 weeks and 5 days though I haven't tested with fmu since 4 weeks and 3 days. So I'm driving myself insane NEVER in my life have I had a period only last two days and be that light. And it is also worrying me because I have this IUD in which increases the likelyhood of all sorts of problems if I'm pregnant so I wanna know asap. I also forgot probably starting a week or so after we had sex nausea started kicking my ass everytime I wanna eat, think about eating, or do eat I feel like I'm about to puke. So I've barely been eating because of it. Which is ultimately making things worse since I've barely been eating. Also since probably about 5 or 6 days after we had sex my nipples have been very sensitive and my boobs have never hurt or anything like that around pms or anything.

What do you think?

Should I go get a blood test done or try to wait it out?

My main concern is the IUD.

Even if I am pregnant and don't get it removed they can keep a close eye on the baby and then IUD.