That is really tough to interpret because there is only so much that temps alone can tell you.
A few things though...
1. If you are having irregular cycles like that... 33 days one month and then 62 the next, you should seriously consider having your doctor test you for PCOS. Irregular cycles is one of the biggest symptoms of PCOS.
2. You really should try to document something about your cm. If you are having a hard time determining which is ewcm and which is semen, you can always use the "Glass of Water" trick. Drop some of the "fluid" into the water. If it dissolves, it was semen. If it forms a ball and sinks, it was ewcm.
3. You could also try checking your cm prior to bd'ing... there has got to be
some point of the day when you've got a "clean slate" as it were.
4. 10 DPO can still be fairly early for a HPT. There are lots of postings about BFPs at 9, 10 & 11 DPO... but those are actually considered EARLY positives.
I think it's possible that your body may have geared up to O but didn't actually do it, which may be why your temps were not staying consistently high. Again, I can't really say with any kind of certainty because I have nothing else to corroborate it, like CM or even cervical position... whether it was high, medium, low... soft, medium, firm...
In any event, FF does tend to change it's mind every so often... since you are new to charting and FF has no cycle history for you to go by... the only thing for it, I'm afraid... is time. In a few days things should become much clearer.
I'm not sure if you are TTC or just charting to get familiar with your cycles... but either way, I hope you get the outcome you are seeking!