Hi ladies, I need your help!

I got my IUD removal in August 2nd, but got it done on February 08. But even before that I had the Nexplanon inserted for straight 6 years, you replace device every 3 years. Got my first period on the 16th August.

After my IUD removal, my partner and I had sex on August 7 no condoms. My partner got surgery which he had to rest for about a month and half. NO SEX AT ALL! Got my second period on the September 15-18th.

On the Sept 21& 23rd& 25& 26& 29& 30!.I had sex with my boyfriend.

When should I take a pregnancy test? or wait to see if i missed my period which it usually comes towards the middle of the month Oct 15 expecting my period. I took two test and it came out negative. Is it because I did not have sex with partner after a month and half? or why? I need answers ladies.