Implantation bleeding?

Hi, this is my first post. I normally don't post anything, but decided I need some opinions. I was so sure I was pregnant. My period is always on time. My fiance and I have been trying to get pregnant for months. I'm 37 and I have 3 kids already, my youngest is 14. I didn't have implantation bleeding with any of them. But I did have early pregnancy symptoms. About 3 days ago I started having light cramping (I never cramp before my period) and I started getting nauseous off and off. It is also brought on by smell a lot which is odd because I lost my sense of smell last year when I got the covid vaccine. Now it's back. All of a sudden. I am peeing more frequently and I've started getting headaches off and on throughout the day. Last night I started spotting, light brownish pink. This morning, pad looks the same, hardly anything on it, and it has stayed that way all morning. But when I go to pee it drips out and is a darker brownish red. It's not heavy like my period usually is, but it is heavier than I expected implantation bleeding to be. No clots, very watery. I have not taken a pregnancy test yet. The store is out of everything except the expensive ones and I don't want to waste my time with the doctor unless I have a positive home test. Thanks for any opinions and/or experiences that you share!